排序方式: 共有55条查询结果,搜索用时 15 毫秒
51.
Savoye S Goutelard F Beaucaire C Charles Y Fayette A Herbette M Larabi Y Coelho D 《Journal of contaminant hydrology》2011,125(1-4):102-112
Heat generated by high level radioactive wastes could alter the performance of a clay repository. It was intended to investigate the effect of such a thermal period on the diffusive properties of Callovo-Oxfordian claystones. Thus, through-diffusion experiments with HTO, Cl-36, Na-22 and Cs-137 were performed before, during and after stages of heating at 80°C that lasted for up to one year. A special attention was paid to limit the occurrence of any chemical disturbance. Therefore (i) the temperature was raised to 80°C, then progressively brought back to 21°C, thanks to three intermediate temperature stages, and (ii) specific synthetic solutions were used for each temperature, chemistry of which being close to the equilibrium state, especially with respect to the carbonate and sulphate minerals. It was found that experiments carried out at 80°C showed a clear increase of the effective diffusion coefficient values for the four tracers with respect to those obtained at 21°C (by a factor of 3 for HTO and Cl-36, 5 for Na-22 and 2 for Cs-137). On the other hand, the porosity and rock capacity values did not exhibit any significant discrepancy between 21°C and 80°C, indicating no observable damage of both the pore conducing network and the sorption properties of clay minerals. The Stokes-Einstein relationship, based on the temperature dependency of the viscosity of bulk water, could be used to describe the temperature dependence of the diffusion of HTO and Cl-36 but failed to describe the diffusive evolution of the two sorbing cations, Na-22 and Cs-137. Furthermore, experiments performed after the thermal period led to diffusive properties well matching those obtained before heating. All these results suggest that at the lab scale the heating of rock samples would not alter the claystone containment properties. 相似文献
52.
Denis A. Coelho Carla S.D. Tavares Tânia M. Lima Miguel L. Lourenço 《International journal of occupational safety and ergonomics》2018,24(3):475-486
Introduction. The effect of different kinds of work on the psychosocial assessment of workers under the same management and organizational environment is investigated. Methods. A voluntary assessment in a utility company was carried out using the short version of the Copenhagen psychosocial questionnaire (CoPsoQ) on two occasions, 1.5 years apart. Initially, 25 office workers (11 men and 14 women) participated, while 14 of those workers (8 women and 6 men) participated in the second assessment together with 32 field workers. The sewage, water treatment and maintenance workers, totaling 32 men, also participated in a field ergonomics assessment using the Washington State Department of Labor and Industries field work ergonomic checklist. Results. The longitudinal outlook was fairly stable, with sustained severe scores in many CoPsoQ subscales and intensification of severity of workers’ control over work and esteem for men. A significantly higher esteem score resulted for field rather than office workers. Workers subjected to foul odors showed similar severity of psychosocial factors. Discussion. For most psychosocial dimensions, the organizational design and management system in place, as well as the overall cultural environment in which it operates, create a much stronger and more decisive impact than job-specific factors. 相似文献
53.
Costa Maria Angélica Martins da Silva Bruno Menezes de Almeida Sâmilla Gabriella Coelho Felizardo Marcos Paulo Costa Ana Flávia Martins Cardoso Arnaldo Alves Dussán Kelly Johana 《Environmental science and pollution research international》2023,30(4):8835-8852
Environmental Science and Pollution Research - Energy demand has increased worldwide, and biomass burning is one of the solutions most used by industries, especially in countries that have a great... 相似文献
54.
Radhouani H Igrejas G Pinto L Gonçalves A Coelho C Rodrigues J Poeta P 《Journal of environmental monitoring : JEM》2011,13(8):2227-2233
Antimicrobial resistance and the mechanisms implicated were studied in 54 enterococci recovered from 57 seagull fecal samples. Almost 78% of the recovered enterococci showed resistance against one or more antibiotics and these isolates were identified to the species level. E. faecium was the most prevalent species (52.4%). High percentages of erythromycin and tetracycline resistances were found among our isolates (95.2%), and lower percentages were identified to other antibiotics. Most of the tetracycline-resistant strains carried the tet(M) and/or tet(L) genes. Genes associated with Tn916/Tn1545 and/or Tn5397 transposons were detected in 45% of tetracycline-resistant isolates. The erm(B) gene was detected in 65% of erythromycin-resistant isolates. The vat(D) and vat(E) genes were present in 5.9% and 11.8% of quinupristin/dalfopristin-resistant isolates, respectively. The ant(6)-Ia gene was identified in 57.1% of streptomycin-resistant isolates. All nine kanamycin-resistant isolates carried the aph(3)'-IIIa gene. The cat(A) gene was found in two chloramphenicol-resistant isolates. Seagulls should be considered a risk species for spreading in the environment antimicrobial resistant enterococci and can serve as a sentinel for antibiotic pressure from the surrounding farm and urban setting. 相似文献
55.
Bárbara Marinho Carlos Coelho Magnus Larson Hans Hanson 《Journal of Coastal Conservation》2018,22(3):475-489
Dredged material resulting from deepening and maintenance activities of the Aveiro Harbor inlet channel, northwestern coast of Portugal, has been used to mitigate the erosion trend recorded on nearby beaches (from Barra to Costa Nova Beach) through direct placement of sand by using standard dredge equipment. The disposal activities of dredged material have been undertaken at two main sites: between the south breakwater and the 1st groin of Costa Nova (dumping area 1, DA1) and between the 3rd and the 5th groin of Costa Nova (dumping area 2, DA2).The sand was placed in the nearshore, between the ?2 and ?7 m Chart Datum, CD, contours.In this study, short- and long-term coastal morphologic changes in the sea bottom, in response to several nourishment operations and to the incoming waves, within the dumping area boundaries are investigated based on a data set of hydrographic surveys collected annually, just before and after the nourishments, between 2009 and 2015. Preliminary results describing the main morphologic changes, evolution trends, sediment budget variations, and nourishments performance are discussed using mainly Geographic Information System techniques. Overall, the analysis demonstrates that the short-term losses in the dumping areas (one month of interval) can reach 50% of the nourished volume, revealing a significant movement of the fill material towards offshore. Seasonal variations promoting cross-shore material exchange can also prevail and misrepresent the sediment balances, if the monitoring area is not comprehensive. Furthermore, some bathymetric analysis suggested that longshore transport gradients have moved the fill material from Barra beach to downdrift areas. All the obtained results contribute to the ongoing discussion about the effectiveness of nearshore sand placements especially in context of an energetic environment. 相似文献