Prevenção de riscos profissionais na construção de edifícios com estruturas em aço leve

A utilização de estruturas em aço leve em edifícios de pequeno porte tem tido um assinalável crescimento nos últimos anos, em diversos países do mundo, fruto das suas assinaláveis vantagens em termos custos, sistematização da produção, facilidade de montagem e de rapidez de execução. As caraterísticas deste sistema construtivo contribuem para a diminuição dos riscos profissionais normalmente associados à execução de estruturas tradicionais, em função da leveza dos elementos estruturais constituintes, da simplicidade das ligações, da repetição das operações de montagem, etc. Mas também introduzem outros riscos que importa considerar no planeamento da segurança de obras deste tipo, nomeadamente, os que resultam da falta de sedimentação das equipas de trabalho, frequentemente associada à sua inexperiência e informalidade, em virtude da simplicidade e da rapidez de construção permitidas pelo sistema. Relevam aqui os riscos de natureza organizacional, sem por de parte os riscos físicos, principalmente relacionados com as operações de montagem, cuja importância vem crescendo à medida que este sistema construtivo vai tendo aplicações em projetos mais complexos e em obras de maior porte. Levantam-se então, para este tipo de obras preocupações diferentes na prevenção de riscos profissionais, quando comparadas com as obras tradicionais. Ao congregar um vasto conjunto de países ibero-americanos em que este sistema construtivo tem tido grande recetividade, a rede temática CYTED despoletou a reflexão sobre este tema, como se procura analisar na presente comunicação.The use of lightweight steel frame structures in small buildings has had a remarkable growth in recent years in many countries, because of their remarkable advantages in costs, production organization, ease of fitting and execution speed. The characteristics of this building system contribute for the reduction of occupational risks normally associated to conventional building structures, due to the lightness of the structural constituents, the simplicity of connections, the repetition of assembly operations, etc. But also introduce other relevant risks in safety planning, including those resulting from the lack of settling of work teams, often associated with inexperience and informality, due to the simplicity and construction provided by the system. Organizational risks are relevant under this topic as well as the increase of physical risks, mainly related to the assembly operations, the importance of which tends to increase as the system is used in more complex projects and larger works. In view of the above, different concerns in the prevention of occupational risks may arise for this type of works, when compared to traditional construction. By bringing a wide range of Latin American countries in which this system has had considerable receptivity, the thematic network CYTED triggered the debate on this issue, as analysed in this paper

Overview on mentha and thymus polyphenols

Mentha and Thymus are important genera of the Lamiaceae family widely distributed in the entire World and commonly used in traditional medicine. Indeed, many species of the two genera have been credited with a large list of health-benefit effects, including antioxidant, anti-inflammatory, antimicrobial, analgesic, neuroprotective and anticarcinogenic. In turn, these properties have been associated to the polyphenolic composition of the plants. The present review summarizes the phenolic constituents found in Mentha and Thymus genera, as well as the main methods applied in their extraction, purification and identification. Reported species of Mentha and Thymus usually comprise derivatives of caffeic acid and distinct glycosidic forms of the flavonoids luteolin, apigenin, eriodictyol and naringenin. At present, the phenolic composition of many relevant plants of Mentha and Thymus is still unknown and thus, more studies are required for the adequate phenolic characterization of these two genera. In this context, the present implementation of faster and reliable analytical methodologies, as e.g. the chromatographic techniques hyphenated with mass spectrometry, will surely be an enormous tool in the upgrading of the missing information

Documentos de prevenção de riscos profissionais na construção na transposição das diretivas comunitárias para Portugal

A Diretiva Comunitária nº 92/57/CEE (Diretiva Estaleiros Temporários ou Móveis) foi transposta pela generalidade dos países europeus nos anos seguintes ao da sua publicação. Se bem que o documento de base para a transposição seja o mesmo, cada país europeu teve necessidade de o adaptar à sua realidade legislativa, durante o processo de transposição, observando-se, hoje em dia, algumas diferenças entre os instrumentos legais em vigor nos diversos países. Em Portugal, a transposição da Diretiva teve lugar em 1995, mas o instrumento legal atualmente em vigor data de 2003 (Decreto-Lei nº 273/2003, de 29 de Outubro). O diploma estipula quatro documentos essenciais de prevenção dos riscos profissionais em estaleiros de construção: – o plano de segurança e saúde, a comunicação prévia, as fichas de procedimentos de segurança e a compilação técnica – e introduz novos intervenientes no processo da construção – os coordenadores de segurança e saúde – explicitando as suas funções e obrigações. A rede temática CYTED tem permitido observar as diferenças de abordagens da prevenção de riscos profissionais em países ibero-americanos e identificar as suas melhores práticas no sentido do usufruto comum. Ao mesmo tempo, revelou algumas especificidades interessantes da prática de cada país da rede, que importa partilhar e refletir. Esta comunicação apresenta algumas especificidades da prática Portuguesa que se analisam sumariamente: a adoção de um só documento de prevenção de riscos profissionais da fase de construção, transversal a todo o processo construtivo; a sua simplificação por fichas de utilização mais prática, quando estão em causa pequenos trabalhos tipificados; a constituição de um documento de prevenção para a fase de utilização do empreendimento construído, da responsabilidade do dono da obraThe Community Directive No. 92/57/EEC (Temorary or Mobile sites Directive) has been implemented by most European countries in the years following its publication. While the basic document for the implementation is the same, each European country had to adapt it to its legislative reality, during the transposition process; therefore, various differences between the legal instruments in force in different countries may be observed, nowadays. In Portugal, the transposition of the Directive took place in 1995, but the legal instrument currently in force dates from 2003 (Decree-Law No. 273/2003 of 29 October). The law stipulates four essential documents for the prevention of occupational risks on construction sites: - the health and safety plan, the prior notice, the safety procedures and technical file - and introduces new actors in the construction process - health and safety coordinators - explaining their duties and obligations. The thematic network CYTED has allowed to observe differences between the approaches followed in Ibero-American countries for occupational risk prevention and identified their best practices for mutual benefit. At the same time, it revealed some interesting specifics in the practices of each country in the network, that it is interesting to share and reflect. This paper presents some specificities of Portuguese practice that are briefly analysed: the adoption of a single document for occupational risks prevention of in construction, across the whole construction process; the simplificationof this document through more easy to use forms usable for smaller works; the creation of a document to prevent the utilization phase of the project under the responsibility of the developer

Olive Mill wastewater bioremediation by Bjerkandera paranensis: a sustainability and technological evaluation

Remediation of olive mill wastewater (OMW) is an important issue associated with olive-oil manufacturing, a widespread activity in the Mediterranean area. This high organic loading effluent contains water, organic acids, high-molecular-weight polyphenols such as tannins, antocyanins and catechins, which are considered to be responsible for its brownish black colour and toxic properties. The composition of OMWs is highly variable with respect to each individual component, depending on the process conditions and on the agricultural specificities. In this work, the ability of a “white-rot” fungus, Bjerkandera paranensis, to use undiluted OMW from a two phase process mill (COD = 11.1 gl-1; Phenol Content = 3.9 gl-1; ColourAbs395nm = 7.8) as a substrate was studied. The biodegradation potential of B. paranensis was assessed monitoring several physico-chemical parameters. A chronic ecotoxicity test (Vibrio fisheri growth inhibition test) was carried out to follow the detoxification ability of this fungus. In work, the results demonstrate that OMW was a suitable medium for cultivation of B. paranensis, with corresponding changes in the physico-chemical properties of the OMW. The results showed that B. paranensis removed 93% phenols and 54% COD from the culture medium within 21 days of treatment. In addition, the IC50s values obtained for the different treated samples showed a significant decrease in the effluent chronic toxicity to V. fischeri when the OMW pH was adjusted to 6.0 prior to the treatment (71.8 %), highlighting the OMW detoxification capacity of B. paranensi

New approaches to olive mill wastes bioremediation

Remediation of olive mill wastewater (OMW) is an important issue associated with olive-oil manufacturing, a widespread activity in the Mediterranean area. This high organic loading effluent contains water, organic acids, high-molecular-weight polyphenols such as tannins, antocyanins and catechins, which are considered to be responsible for its brownish black colour and ecotoxic properties. The composition of OMWs is highly variable with respect to each individual component, depending on the process conditions and on the agricultural specificities. Thus, different approaches are applicable concerning to OMW treatment and valorisation , considering the specificities of its production and in particular the oil extraction process. Besides there are several physical, physico-chemical, biological and combined processes to OMW detoxification, each may represent an opportunity for a specific condition. It is important to explore new possibilities that are both environmentally sustainable and economically viable. Under the biological processes the use of fungi and in particular white-rot fungi present a potential interesting alternative for depollution and biological chemicals production or for protein production for feeding. In this aspect we have been testing the ability of a “white-rot” fungus, Bjerkandera paranensis, to use undiluted OMW from a two phase process mill. A chronic ecotoxicity test (Vibrio fisheri growth inhibition test) demonstrated that the growth of this fungus contributed for a significant decrease of the OMW ecotoxicity and demonstrating the potential for further studies with this strain for an alternative biological route to OMW treatment and valorization

Thymus citriodorus: phenolic characterization and antioxidant activity

The present work aims to determine the phenolic composition of Thymus citriodorus and to estimate its antioxidant capacity. An ethanolic extract was prepared from the plant and its total phenolic and flavone contents were determined. The phenolic extract was fractionated by reversed-phase HPLC and the major phenolic compounds of each fraction were identified by ESI-MS and MSn analysis, in order to establish the specific phenolic profile of the plant. The total phenolic compounds in the ethanolic extract of Thymus citriodorus accounted for 138,75±13,56 mg/g, and its content of flavones was estimated as 27,30±2,15 mg/g. Moreover, the interpretation of the fragmentation pathways under ESI-MS/MS of the collected HPLC fractions allowed concluding that the major phenolic compounds in the plant included some glycoside derivatives of luteonin, naringenin and eriodictyol. Also, the phenolic extract showed a considerable antioxidant activity, as evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging potential and the reducing potential, suggesting that Thymus citriodorus can be an important source of natural antioxidants

Mentha aquatica: source of flavanone glycosides

Mentha aquatica L., commonly known as water mint, is a perennial herb that grows in Europe temperate regions. This plant is used in traditional medicine for the treatment of external inflammation, rheumatism, colds, respiratory problems and difficult menstruation [1]. It has been described as a good source of phenolic compounds with high scavenger activity [2]. In this study, a purified ethanolic extract of M. aquatica was prepared and its specific phenolic composition was determined. The extract of the aerial parts of M. aquatica was prepared according the procedure described by Pereira et al [3] and analyzed by high performance liquid chromatography with diode array detection with quantification of main phenolic compounds, using the external standard method. In order to determine the exact structure of phenolic compounds, the HPLC eluted fractions were manually collected and further analyzed by tandem electrospray mass spectrometry. The purified ethanolic extract of M. aquatica was mainly rich in flavanones comprises eriodictyol, hesperitin and naringenin glycosides. Moreover, the purified ethanolic extract of M. aquatica contained moderate amounts of rosmarinic acid, a phenolic acid very common in Mentha species and in Lamiaceae family

New biophenols in olive mill wastewaters

Olive mill wastewaters (OMW) have been attracting the attention of food and pharmaceutical industries, as it is a potential source of biophenols with a wide range of biological activities. This effluent produced in the olive oil industry contains approximately half of the total phenolic compounds of the olive fruit and it is currently exploited for industrial extraction of hydroxytyrosol [1]. Still, the phenolic composition of OMW is extremely complex, and many compounds are yet unidentified. In this context, the identification of unknown phenolic compounds can encourage the search of new bioactive compounds in OMW and contribute to further valorize this waste. In the present work, six new phenolic compounds were identified in Portuguese olive mill wastewaters. The phenolic extracts of OMW were obtained by methanol and were fractionated on Sep Pack C18 cartridges, by elution of the cartridges with 50% (v/v) methanol. The analysis of the purified fractions by electrospray mass spectrometry in the negative mode showed high relative abundant [M-H]− ions at m/z 539 and m/z 523, corresponding respectively to oleuropein and ligstroside isomers that contain the glucose unit linked to its hydroxytyrosol moiety. Glucoside derivatives of these compounds were also found in the two OMW samples. In particular, the fragmentation pathway of the [M-H]− ion at m/z 863 demonstrated the presence of a diglucoside derivative of the oleuropein isomer, while those of the ions at m/z 685 and m/z 847 were consistent with mono- and a di-glucosides of the ligstroside isomer, respectively. Moreover, the structure of an elenoic derivative of the ion at m/z 685 was also elucidated. Studies regarding the abundance and the biological activities of these compounds are now required to determine their possible industrial exploitation. [1] Agallias A., Magiatis P., Skaltsounis A.-P., Mikros E., Tsarbopoulos A., Gikas E., Spanos I., Manios T. (2007). J. Agric. Food Chem. 55: 2671-2676

Valorização das águas ruças – Identificação de compostos antioxidantes

Neste trabalho pretendeu-se determinar a composição em compostos fenólicos de amostras de efluentes líquidos provenientes de diferentes lagares de azeite do Norte de Portugal (Amarante, Mirandela, Castelo Rodrigo e Frieira). Para tal, as águas ruças foram extraídas com acetato de etilo, o extracto foi fraccionado por HPLC e as fracções foram analisadas por espectrometria de massa (ESI-MS e ESI-MSn). Este procedimento permitiu verificar que o composto maioritário era o hidroxitirosol, embora em concentração variável. As amostras continham ainda outros compostos fenólicos comuns, tais como o ácido clorogénico, o ácido cafeico, o ácido p-cumárico, o tirosol; secoiridoides como o ácido elenólico, o oleosideo, o verbascosídeo, a oleuropeína, o ligostrosídeo e alguns flavonóides como a luteolina, a quercetina e o glucosídeo da luteolina.This study intended to determine the composition of phenolic compounds in different olive wastewaters collected in the North of Portugal (Amarante, Mirandela, Castelo Rodrigo and Frieira). The samples were extracted with ethyl acetate, the extract was fractionated by HPLC and the fractions were analyzed by mass spectrometry (ESI-MS and ESI-MSn). Hydroxytyrosol was the main phenolic compound, although with variable concentrations. The samples also contained other common phenolic compounds such as chlorogenic acid, caffeic acid, p-coumaric acid, tyrosol; secoiridoids like elenolic acid, oleoside, verbascoside, oleuropein, ligostroside and some flavonoids like luteolin, quercetin and luteolin glycoside.FC

Phenolic composition of four sage species: salvia farinacea, salvia mexico, salvia greggii and salvia officinalis

Salvia species are used worldwide for medicine purposes. In general, these medicinal plants have high amounts of flavonoids and phenolic acids, that are thought to be closely related to their health properties [1,2]. In this work, the aerial parts of Salvia farinacea, Salvia mexico, Salvia greggii and Salvia officinalis were extracted with hot water [3]. Extracts were evaluated for their total phenolic content by an adaptation of the Folin-Ciocalteu method and further analysed by high performance liquid chromatography associated with electrospray mass spectrometry (HPLC-DAD-ESI-MSn) in the negative ion mode [4], in order to identify their individual phenolic constituents. The aqueous extracts of S. farinacea, S. mexico, S. officinalis and S. greggii contained, respectively, 106±13, 159±38, 175±46 and 136±1 μg GAE/mg of total phenolics. These four species were characterized by a clear prevalence of caffeic acid derivatives, in particular of rosmarinic acid (MW 360), that is generally the most abundant phenolic compound in Salvia species [2,3]. In addition, S. mexico and S. officinalis contained moderate amounts of salvianolic acid B (MW 718). Among these two, S. mexico was richer in O-caffeoylquinic acid (MW 354), while the latter presented high amounts of salvianolic acid K (MW 556) and moderate amounts of its structural isomer. All the extracts were enriched in flavones: S. farinacea and S. officinalis contained high amounts of luteolin-O-glucuronide while S. mexico contained luteolin-C-glucoside with respective characteristic mass spectrometry fragmentation pattern m/z at 461→285 and m/z at 447→357, 327. Similarly, S. greggii extract presented high content of luteolin-7-O-glucoside ([M-H]− at m/z 447→ 285) and luteolin-C-glucoside and moderate quantities of apigenin-C-hexoside ([M-H]− at m/z 431→341, 311). Further studies are being undertaken in order to understand the contribution of these phenolic constituents in the biological activities of Salvia plants