976 resultados para Biodegradation of cork
Resumo:
Cork oak is the second most dominant forest species in Portugal and makes this country the world leader in cork export. Occupational exposure to Chrysonilia sitophila and the Penicillium glabrum complex in cork industry is common, and the latter fungus is associated with suberosis. However, as conventional methods seem to underestimate its presence in occupational environments, the aim of our study was to see whether information obtained by polymerase chain reaction (PCR), a molecular-based method, can complement conventional findings and give a better insight into occupational exposure of cork industry workers. We assessed fungal contamination with the P. glabrum complex in three cork manufacturing plants in the outskirts of Lisbon using both conventional and molecular methods. Conventional culturing failed to detect the fungus at six sampling sites in which PCR did detect it. This confirms our assumption that the use of complementing methods can provide information for a more accurate assessment of occupational exposure to the P. glabrum complex in cork industry.
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This dissertation presents a comparative study of three factories in Cork Harbour area, Sunbeam Wolsey (1927-90), Irish Steel (1939-2001) and the Ford Marina Plant (1917-84). All three factories were significant industrial employers in both a domestic (Irish) and a local (Cork) context and are broadly representative of the Irish manufacturing industry that was developed under the policies of tariff protection introduced in the 1930s and gradually phased out between the late 1950s and the mid-1980s. Sunbeam Wolsey was a textile and clothing concern located on the north side of Cork City that possessed a borderline monopoly within its economic sector and was among the largest private employers of female labour in twentieth century Ireland. Irish Steel was the country’s only steel mill, located on Haulbowline island, a brief ferry-ride from the seaside town of Cobh, and was unusual in being one of the few manufacturing concerns operated as a nationalised industry under the auspices of the state. The Ford Marina plant predated the introduction of protectionism by more than a decade and began as the centre of the Ford empire’s tractor manufacturing business, before switching to the production of private motor vehicles for the Irish market in 1932. All three industries were closed or sold off when the state withdrew support, either in the form of tariff protection (Ford, Sunbeam) or direct funding (Irish Steel). While devoting much attention to the three firms, the central concern of this dissertation is not the companies themselves (though the economic history portion of the dissertation is substantial), but the workers they employed, examining the lives of these individuals both as members of the Irish working class, and, more specifically, as employees of the three factories under consideration. The project can be best described as a comparative factory study, comparing and contrasting the three workforces, focusing primarily on industrial relation and the experience of work. This dissertation utilises both documentary evidence and a significant quantity of oral testimony, breaking new ground by making the workplace the central focus of its investigation. The principal aims of the study are: 1. To document the lives of those who worked in these factories, capturing through oral testimony their subjective experiences of social class and factory life, as well as differences among narrators in terms of gender and status. In achieving this aim, the study will provide a broader social context for its detailed analysis of work and industrial relations in each firm. 2. To analyse the three workplaces and determine how and why each developed such distinct systems of industrial relations at the factory level, as well as to compare and contrast these systems. 3. To examine the nature of work in each factory and to determine how work and industrial relations in each firm developed over time, relating these changes both to internal and external factors. Additionally, the project will provide a comparative analysis of these changes.
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Use of activated charcoal and ion-exchange resin to cleaN up and concentrate enzymes in extracts from biodegraded wood. Ceriporiopsis subvermispora was used for the biodegradation of Eucalyptus grandis chips in the presence or absence of co-substrates (glucose and corn steep liquor) during 7, 14 and 28 days. Afterwards, the biodegraded chips were extracted with 50 mM sodium acetate buffer (pH 5.5) supplemented with 0.01% Tween 60. High activities of manganese peroxidases (MnPs) were observed in all the extracts, both in the absence (430, 765 and 896 UI kg(-1) respectively) and in the presence of co-substrates (1,013; 2,066 and 2,323 UI kg(-1) respectively). The extracts presented a high ratio between absorbances at 280 and 405 nm, indicating a strong abundance of aromatic compounds derived from lignin over heme-peroxidases. Adsorption into activated charcoal showed to be an adequate strategy to reduce the absorbance at 280 urn in all the extracts. Moreover, it allowed to maximize the capacity of an anion exchange resin bed (DEAE-Sepharose) used to concentrate the MnPs present in the extracts. It was concluded that the use of activated charcoal followed by adsorption into DEAE Sepharose is a strategy that can be used to concentrate MnPs in extracts obtained during the biodegradation of E. grandis by C. subvermispora.
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PLA microparticles containing 17-beta-estradiol valerate were prepared by an emulsion/evaporation method in order to sustain drug release. This system was characterized concerning particle size, particle morphology and the influence of formulation and processing parameters on drug encapsulation and in vitro drug release. The biodegradation of the microparticles was observed by tissue histological analysis. Scanning electron microscopy and particle size analysis showed that the microparticles were spherical, presenting non-aggregated homogeneous surface and had diameters in the range of 718-880 nm (inert microparticles) and 3-4 mu m (drug loaded microparticles). The encapsulation efficiency was similar to 80%. Hormone released from microparticles was sustained. An in vivo degradation experiment confirmed that microparticles are biodegradable. The preparation method was shown to be suitable, since the morphological characteristics and efficiency yield were satisfactory. Thus, the method of developed microparticles seems to be a promising system for sustained release of 17-beta-estradiol.
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The environmental fate of polycyclic aromatic hydrocarbons (PAHs) in soils is motivated by their wide distribution, high persistence, and potentially deleterious effect on human health. Polycyclic aromatic hydrocarbons constitute the largest group of environmental contaminants released in the environment. Therefore, the potential biodegradation of these compounds is of vital importance. A biocarrier suitable for the colonization by micro-organisms for the purpose of purifying soil contaminated by polycyclic aromatic hydrocarbons was developed. The optimized composition of the biocarrier was polyvinyl alcohol (PVA) 10%, sodium alginate (SA) 0.5%, and powdered activated carbon (PAC) 5%. There was no observable cytotoxicity of biocarriers on immobilized cells and a viable cell population of 1.86 x 10(10) g(-1) was maintained for immobilized bacterium. Biocarriers made from chemical methods had a higher biodegradation but lower mechanical strengths. Immobilized bacterium Zoogloea sp. had an ideal capability of biodegradation for phenanthrene and pyrene over a relative wide concentration range. The study results showed that the biodegradation of phenanthrene and pyrene reached 87.0 and 75.4%, respectively, by using the optimal immobilized method of Zoogloea sp. cultivated in a sterilized soil. Immobilized Zoogloea sp. was found to be effective for biodegrading the soil contaminated with phenanthrene and pyrene. Even in natural (unsterilized) soil, the biodegradation of phenanthrene and pyrene using immobilized Zoogloea sp. reached 85.0 and 67.1%, respectively, after 168 h of cultivation, more than twice that achieved if the cells were not immobilized on the biocarrier. Therefore, the immobilization technology enhanced the competitive ability of introduced micro-organisms and represents an effective method for the biotreatment of soil contaminated with phenanthrene and pyrene.
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Nanofiltration process for the treatment/valorisation of cork processing wastewaters was studied. A DS-5 DK 20/40 (GE Water Technologies) nanofiltration membrane/module was used, having 2.09 m(2) of surface area. Hydraulic permeability was determined with pure water and the result was 5.2 L.h(-1).m(-2).bar(-1). The membrane presents a rejection of 51% and 99% for NaCl and MgSO4 salts, respectively. Two different types of regimes were used in the wastewaters filtration process, total recycling mode and concentration mode. The first filtration regime showed that the most favourable working transmembrane pressure was 7 bar working at 25 degrees C. For the concentration mode experiments it was observed a 30% decline of the permeate fluxes when a volumetric concentration factor of 5 was reached. The permeate COD, BOD5, colour and TOC rejection values remained well above the 90% value, which allows, therefore, the concentration of organic matter (namely the tannin fraction) in the concentrate stream that can be further used by other industries. The permeate characterization showed that it cannot be directly discharged to the environment as it does not fulfil the values of the Portuguese discharge legislation. However, the permeate stream can be recycled to the process (boiling tanks) as it presents no colour and low TOC (< 60 ppm) or if wastewater discharge is envisaged we have observed that the permeate biodegradability is higher than 0.5, which renders conventional wastewater treatments feasible.
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Neste caso de estudo apresentam-se as acções de Responsabilidade Social e Sustentabilidade das organizações envolvidas no Programa GREEN CORK, assim como alguns aspectos relacionados com marketing verde. O GREEN CORK é um Programa de Reciclagem de rolhas de cortiça que permite o financiamento de parte do Programa “CRIAR BOSQUES, CONSERVAR A BIODIVERSIDADE”, que utilizará exclusivamente árvores que constituem a nossa floresta autóctone. “ROLHAS POR QUERCUS” é a mensagem do Programa GREEN CORK.
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Cork is a light, porous and impermeable material extracted from the bark of some trees. It is in manufacture of stoppers for wine bottles the main application of cork. It is estimated that the area occupied by cork oaks in the Iberian Peninsula is around 33% in Portugal and 23% in Spain. The world production of cork is focused in the south Europe, with Portugal being the most important producer followed by Spain. According to Companies Directory more than 100 manufactories from Portugal has their branch associated with the preparation and fabrication of cork. Cork workers are at risk for developing diseases of the respiratory tract such as occupational asthma and Suberosis, a form of pulmonary hypersensitivity due to repeated exposure to mouldy cork dust. In this review study papers from 2000 were analyzed to better understand which fungi species are associated with occupational disease in cork workers. The most prevalent fungi species in these workers that are associated with those occupational diseases are Penicilliumglabrum, Chrysoniliasitophila and Trichodermalongibrachiatum. Therefore, a specific knowledge about occupational exposure to fungi in the cork industry is the key to better understand the related diseases and to define preventive measures. Given the importance of this occupational setting in Portugal is essential to evaluate the combined exposure of fungi and particles and their metabolites. Further studies concerning exposure assessment to fungi and particles in the cork industry must be developed.
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Purpose Polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds commonly found as soil contaminants. Fungal degradation is considered as an environmentally friendly and cost-effective approach to remove PAHs from soil. Acenaphthylene (Ace) and Benzo[a]anthracene (BaA) are two PAHs that can coexist in soils; however, the influence of the presence of each other on their biodegradation has not been studied. The biodegradation of Ace and BaA, alone and in mixtures, by the white rot fungus Pleurotus ostreatus was studied in a sandy soil. Materials and methods Experimental microcosms containing soil spiked with different concentrations of Ace and BaAwere inoculated with P. ostreatus. Initial (t 0) and final (after 15 days of incubation) soil concentrations of Ace and BaA were determined after extraction of the PAHs. Results and discussion P. ostreatus was able to degrade 57.7% of the Ace in soil spiked at 30 mg kg−1 dry soil and 65.8% of Ace in soil spiked at 60 mg kg−1 dry soil. The degradation efficiency of BaA by P. ostreatus was 86.7 and 77.4% in soil spiked with Ace at 30 and 60 mg kg−1 dry soil, respectively. After 15 days of incubation, there were no significant differences in Ace concentration between soil spiked with Ace and soil spiked with Ace + BaA, irrespective of the initial soil concentration of both PAHs. There were also no differences in BaA concentration between soil spiked with BaA and soil spiked with BaA + Ace. Conclusions The results indicate that the fungal degradation of Ace and BaA was not influenced by the presence of each other’s PAH in sandy soil. Bioremediation of soils contaminated with Ace and BaA using P. ostreatus is a promising approach to eliminate these PAHs from the environment.
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Aims: The main aims of this work were the study of cork slabs moulds colonization and the evaluation of the moulds diversity during cork processing steps, in different cork stoppers factories. Simultaneously, it was envisaged to perform an evaluation of the air quality. Methods and Results: Moulds were isolated and identified from cork slabs and cork samples in four cork stoppers factories. The identification was based on morphological characters and microscopic observation of the reproductive structures. Airborne spore dispersion was assessed using a two stage Andersen sampler. It was observed that Chrysonilia sitophila was always present on cork slabs during the maturing period, but mould diversity appeared to be associated to the different factory configurations and processing steps. Conclusions: Spatial separation of the different steps of the process, including physical separation of the maturation step, is essential to guarantee high air quality and appropriate cork slabs colonization, i.e. C. sitophila dominance. The sorting and cutting of the edges of cork slabs after boiling and before the maturing step is also recommended. Significance and Impact of the Study: This study is very important for the cork stopper industry as it gives clear indications on how to keep high quality manufacturing standards and how to avoid occupational health problems.
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Aims: The main aims of this work were the study of cork slabs moulds colonization and the evaluation of the moulds diversity during cork processing steps, in different cork stoppers factories. Simultaneously, it was envisaged to perform an evaluation of the air quality. Methods and Results: Moulds were isolated and identified from cork slabs and cork samples in four cork stoppers factories. The identification was based on morphological characters and microscopic observation of the reproductive structures. Airborne spore dispersion was assessed using a two stage Andersen sampler. It was observed that Chrysonilia sitophila was always present on cork slabs during the maturing period, but mould diversity appeared to be associated to the different factory configurations and processing steps. Conclusions: Spatial separation of the different steps of the process, including physical separation of the maturation step, is essential to guarantee high air quality and appropriate cork slabs colonization, i.e. C. sitophila dominance. The sorting and cutting of the edges of cork slabs after boiling and before the maturing step is also recommended. Significance and Impact of the Study: This study is very important for the cork stopper industry as it gives clear indications on how to keep high quality manufacturing standards and how to avoid occupational health problems.
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This paper presents the design of low-cost, conformal UHF antennas and RFID tags on two types of cork substrates: 1) natural cork and 2) agglomerate cork. Such RFID tags find an application in wine bottle and barrel identification, and in addition, they are suitable for numerous antenna-based sensing applications. This paper includes the high-frequency characterization of the selected cork substrates considering the anisotropic behavior of such materials. In addition, the variation of their permittivity values as a function of the humidity is also verified. As a proof-of-concept demonstration, three conformal RFID tags have been implemented on cork, and their performance has been evaluated using both a commercial Alien ALR8800 reader and an in-house measurement setup. The reading of all tags has been checked, and a satisfactory performance has been verified, with reading ranges spanning from 0.3 to 6 m. In addition, this paper discusses how inkjet printing can be applied to cork surfaces, and an RFID tag printed on cork is used as a humidity sensor. Its performance is tested under different humidity conditions, and a good range in excess of 3 m has been achieved, allied to a good sensitivity obtained with a shift of >5 dB in threshold power of the tag for different humid conditions.
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Construction and Building Materials 49 (2013), 315-327
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Current societal challenges increasingly demand the need to seek for efficient and sustainable solutions to daily problems. Construction, as a result of its activity, is one of the main responsible industry for the exploitation of resources and greenhouse gas emissions. In this way, several research works are being undertaken to change some of the current practices. This paper presents the work being done at University of Minho to study de degradation of natural fibers when used as a sustainable solution for soil reinforcement. Jute and sisal fibrous structures (0º/90º) were studied in terms of their degradation over time, when incorporated into soil and when subject to accelerated aging tests in a QUV weathering test equipment. Results show that the process of biodegradation of natural fibers is clearly accelerated by the action of temperature, moisture and solar radiation, explaining further degradation of jute and sisal fibers when exposed to these factors, although more pronounced in jute fabric structures.
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The hydrogen and oxygen isotopes of water and the carbon isotope composition of dissolved inorganic carbon (DIC) from different aquifers at an industrial site, highly contaminated by organic pollutants representing residues of the former gas production, have been used as natural tracers to characterize the hydrologic system. On the basis of their stable isotope compositions as well as the seasonal variations, different groups of waters (precipitation, surface waters, groundwaters and mineral waters) as well as seasonably variable processes of mixing between these waters can clearly be distinguished. In addition, reservoir effects and infiltration rates can be estimated. In the northern part of the site an influence of uprising mineral waters within the Quaternary aquifers, presumably along a fault zone, can be recognized. Marginal infiltration from the Neckar River in the cast and surface water infiltration adjacent to a steep hill on the western edge of the site with an infiltration rate of about one month can also be resolved through the seasonal variation. Quaternary aquifers closer to the centre of the site show no seasonal variations, except for one borehole close to a former mill channel and another borehole adjacent to a rain water channel. Distinct carbon isotope compositions and concentrations of DIC for these different groups of waters reflect variable influence of different components of the natural carbon cycle: dissolution of marine carbonates in the mineral waters, biogenic, soil-derived CO2 in ground- and surface waters, as well as additional influence of atmospheric CO2 for the surface waters. Many Quaternary aquifer waters have, however, distinctly lower delta(13)C(DIC) values and higher DIC concentrations compared to those expected for natural waters. Given the location of contaminated groundwaters at this site but also in the industrially well-developed valley outside of this site, the most likely source for the low C-13(DIC) values is a biodegradation of anthropogenic organic substances, in particular the tar oils at the site.