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Kangaroo Valley, Australia

Opedal M.T.,Norwegian University of Science and Technology | Stenius P.,Centralvagen | Johansson L.,Paper And Fibre Research Institute | Hill J.,PO Box 39 | Hill J.,Norske Skog ASA
Nordic Pulp and Paper Research Journal | Year: 2011

In this paper, we report on an evaluation of the removal of flocculated extractives from two thermomechanical pulp (TMP) process streams: pressate water from an Impressafiner and process water from chip washer by using a flotation technique (Dissolved Air Flotation, DAF). The efficiency of the flotation technique was evaluated by measuring the turbidity, chemical oxygen demand (COD), the amount of extractives and carbohydrates present in the subnatant and amount of lignin. The laboratory tests have shown that the combination of the polymers (C-PAM + PolyDADMAC, mass ratio 1:1) gave the best results, both in the flocculation of colloidal extractives present in the process water and in the efficiency after DAF. Moreover, by using a dissolved air flotation the flocculated extractives could be removed with a removal efficiency of 80-90%.

Opedal M.T.,Norwegian University of Science and Technology | Stenius P.,Centralvagen 18F | Johansson L.,Paper And Fibre Research Institute | Hill J.,PO Box 39 | Hill J.,Norske Skog ASA
Nordic Pulp and Paper Research Journal | Year: 2011

The aim of this study was to investigate the flocculation of colloidal extractives present in pressate water from an Impressafiner with different cationic polymers. A high charge density and low molar mass polymer (poly-DADMAC) and a high molar mass and low charge density polymer (C-PAM) were used in our study. The results indicate that these polymers efficiently flocculate colloidal extractives present in the process water via two different flocculation mechanisms: charge neutralization and bridging flocculation. Moreover, the results are discussed in terms of turbidity, sedimentation rate (Turbiscan) and particle size distribution of flocculated extractives.

Opedal M.T.,Norwegian University of Science and Technology | Opedal M.T.,Paper And Fibre Research Institute | Stenius P.,Centralvagen | Johansson L.,Paper And Fibre Research Institute | And 3 more authors.
Nordic Pulp and Paper Research Journal | Year: 2011

In this paper, we report on an investigationof the removal of dissolved and colloidal substances inwater from compressive pre-treatment of wood chips(process water from compressive pre-treatment) using apilot dissolved air flotation (DAF) unit in a paper mill.The flotation efficiency technique was evaluated bymeasuring turbidity, chemical oxygen demand (COD),and the amounts of extractives, carbohydrates and ligninpresent in the subnatant before and after flotation. Factorssuch as pH and temperature of the pressate water fromcompressive pre-treatment affect the efficiency of DAFand are discussed. The results show that the best removalefficiency (up to 76% removal of extractives) wasobtained by using a combination of a high molecularweight, low charge density polymer (C-PAM) with a lowmolecular weight, high charge density polymer (poly-DADMAC + C-PAM) in the mass ratio 1:1.

Priestley L.T.,Beaverhill Bird Observatory | Priestley C.,STRIX Ecological Consulting | Collister D.M.,Calgary Bird Banding Society | Zazelenchuk D.,PO Box 39 | Hanneman M.,4704 20th Avenue
Journal of Raptor Research | Year: 2010

Researchers banded 4439 Northern Saw-whet Owls (Aegolius acadicus) during autumn at 10 migration-monitoring stations between 2002 and 2007 in Alberta and Saskatchewan, Canada. Sixty-one recaptures of live birds or recoveries of dead birds (together termed "encounters") banded at these stations and recaptures at these stations of birds banded elsewhere occurred during this period. The farthest saw-whet owl encountered was 2315 km from the banding station (Last Mountain Lake, Saskatchewan, to Hebron, Pennsylvania). Almost half of the encounter locations were east or southeast of the associated banding site. The overall average speed of within-season travel was 37 km/night; however, the average speed of eastward movements was 81 km/night (n 9). Of 19 within-season (mid-August to mid-December) encounters, hatch-year females (n 11) travelled farther (615 km ± 464.9) than after-hatch-year females (n 5; 110 km ± 33.6; P 0.047). Three owls apparently overwintered in Alberta and Saskatchewan. During the nonbreeding season, saw-whet owls in Alberta and Saskatchewan may employ more than one movement strategy, including migration, overwintering in the region, and possible nomadism, which suggests that the species is a variable partial migrant. Birds banded at Alberta stations had more southward encounters than those banded at Saskatchewan stations, which were encountered mostly to the southeast, suggesting that autumn movements of saw-whet owl are influenced by the presence of suitable forested habitat. © 2010 The Raptor Research Foundation, Inc.

Introduction: Until recently, multiresistant bacteria were only limited to hospitals. However, they are now responsible for community acquired infections, affecting people who have had no contact with the hospital environment. Several mechanisms are associated with these resistances. The production of betalactamases is however the predominant mechanism and especially the production of extended spectrum beta-lactamases or ESBL by strains of Escherichia coli and Klebsiella pneumoniae, which mediate resistance to third generation cephalosporins and aztreonam (AZT). The association of multiple mechanisms of resistance (efflux pumps, impermeability and enzymatic inactivation) generates multi resistant bacteria such as Pseudomonas aeruginosa MDR and Klebsiella pneumoniae MDR. Aim of the study: The aim of the study was to analyze retrospectively the susceptibility to antibiotics of strains of E. coli, K. pneumoniae, P. aeruginosa and A. baumanii isolated from hospitalized and outpatients in a university hospital center of Beirut over a period of five years from 2005 to 2009. Materials and methods: Bacterial strains were classified according to their origin (inpatients versus outpatients), their ability to produce or not ESBLs for E. coli and K. pneumonia and if they were MDR for P. aeruginosa and A. baumanii. Antibiotics susceptibilities were retrieved from the informatics database of the hospital. Comparison of susceptibility percentages was done using a unilateral z-test on a computer program. Results: In 2009, 2541 strains of E. coli were isolated, 773 of which or 30.4 % were ESBL producers while 2031 strains were isolated in 2005, of which 361 or 17.8 % were ESBL producers (p< 0.001). We noticed a decrease in hospital strains susceptibility to ceftazidime (CAZ) and AZT, between 2005 and 2009 (p< 0.001), and a decrease in community strains susceptibility to triméthoprime/sulfaméthoxazole (SXT) between 2005 and 2009 (p= 0.03). We noted however a significant decrease of ESBL producing strains between 2007 and 2009: 33.4 % versus 30.4 % (p= 0.03). Among 560 strains of K. pneumoniae isolated in 2009, 178 strains or 31.8 % were ESBL producers in comparison to 23.7 % of the strains isolated in 2005 (p= 0.03). We also noticed a decrease in hospital strains susceptibility to piperacilline-tazobactam (TZP), cefotaxime (CTX) and AZT (p< 0.001 p= 0.03 and p= 0.03 respectively) between 2006 and 2009, and a significant increase in ESBL producing strains between 2008 et 2009 (p= 0.0001). 26.5 % of P. aeruginosa strains isolated in 2009 were MDR bacteria with no significant change as compared to 26.6 % in 2005 (p= 0.5). However, the percentage of MDR strains slightly decreased between 2008 and 2009 (p= 0.047). The susceptibility of MDR strains to CAZ and imipenem (IMP) decreased between 2005 and 2009 (p< 0.001 and P = 0.003 respectively). As for A. baumanii, 77.7 % of strains were MDR in 2009 in comparison to 73.4 % in 2005 (p= 0.24) with a dramatic decrease of MDR strains susceptibility to IMP from 92.3 % in 2006 to 30 % in 2009 (p< 0.001). Conclusion: Despite restrictions on antibiotics prescriptions and isolation of patients harboring MDR bacteria or bacteria producing ESBL, there has not been satisfactory reduction of multi resistant bacteria and efforts should be made to reduce these bugs from the hospital flora. © 2011 Elsevier Masson SAS.

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