| 121. |
- Beecken, Jörg, 1982, et al.
(författare)
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Emission factors of SO2, NOx and particles from ships in Neva Bay from ground-based and helicopter-borne measurements and AIS-based modeling
- 2015
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 15:9, s. 5229-5241
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Tidskriftsartikel (refereegranskat)abstract
- Emission factors of SO2, NOx and size-distributed particle numbers were measured for approximately 300 different ships in the Gulf of Finland and Neva Bay area during two campaigns in August/September 2011 and June/July 2012. The measurements were carried out from a harbor vessel and from an Mi-8 helicopter downwind of passing ships. Other measurements were carried out from shore sites near the island of Kronstadt and along the Neva River in the urban area of Saint Petersburg. Most ships were running at reduced speed (10 kn), i.e., not at their optimal load. Vessels for domestic and international shipping were monitored. It was seen that the distribution of the SO2 emission factors is bi-modal, with averages of 4.6 and 18.2 gSO(2) kg(fuel)(-1) for the lower and the higher mode, respectively. The emission factors show compliance with the 1% fuel sulfur content Sulfur Emission Control Areas (SECA) limit for 90% of the vessels in 2011 and 97% in 2012. The distribution of the NOx emission factor is mono-modal, with an average of 58 gNO(x) kg(fuel)(-1). The corresponding emission related to the generated power yields an average of 12.1 gNO(x) kWh(-1). The distribution of the emission factors for particulate number shows that nearly 90% of all particles in the 5.6 nm to 10 mu m size range were below 70 nm in diameter. The distribution of the corresponding emission factors for the mass indicates two separated main modes, one for particles between 30 and 300 nm and the other for above 2 mu m. The average particle emission factors were found to be in the range from 0.7 to 2.7 x 10(16) particles kg(fuel)(-1) and 0.2 to 3.4 gPM kg(fuel)(-1), respectively. The NOx and particulate emissions are comparable with other studies. The measured emission factors were compared, for individual ships, to modeled ones using the Ship Traffic Emission Assessment Model (STEAM) of the Finnish Meteorological Institute. A reasonably good agreement for gaseous sulfur and nitrogen emissions can be seen for ships in international traffic, but significant deviations are found for inland vessels. Regarding particulate mass, the values of the modeled data are about 2-3 times higher than the measured results, which probably reflects the assumptions made in the modeled fuel sulfur content. The sulfur contents in the fuel retrieved from the measurements were lower than the previously used assumptions by the City of Saint Petersburg when carrying out atmospheric modeling, and using these measurements it was possible to better assess the impact of shipping on air quality.
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| 122. |
- Chernoray, Valery, 1975, et al.
(författare)
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Instability of a swept-wing boundary layer modulated by stationary flow perturbations
- 2013
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Ingår i: Visualization of Mechanical Processes: An International Online Journal. - 2152-209X. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- A collection of illustrations of swept-wing boundary layer secondary instability at low subsonic flow velocities is presented in this paper. The experimental results, obtained by hot-wire "visualization," provide detailed insight into the spatio-temporal structure and evolution of oscillations in the three-dimensional laminar boundary layer disturbed by longitudinal vortices and streaky structures.
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| 123. |
- Chernoray, Valery, 1975, et al.
(författare)
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Riblet-assisted control of transformation of the Λ-structure into a turbulent spot
- 2005
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Ingår i: Thermophysics and Aeromechanics. - 0869-8643. ; 12:4, s. 539-548
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Tidskriftsartikel (refereegranskat)abstract
- Experimental results are presented on transformation of a solitary Λ-structure into a turbulent spot and control of this process by means of riblets on the wetted surface in the boundary layer on a flat plate. It is shown that riblets exert a stabilizing effect on transformation of the Λ-structure into a turbulent spot. The Λ-structure on a smooth surface is shown to stretch in the streamwise direction and transform into a hairpin vortex, which becomes a turbulent spot further downstream. The intensity of the Λ-structure on riblets first increases and then decays further downstream, reaching less than half its value on a smooth surface. Finally, the Λ-structure decays on riblets without forming a turbulent spot.
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| 124. |
- Chernoray, Valery, 1975, et al.
(författare)
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Spatial hot-wire visualization of the Lambda-structure transformation into the turbulent spot on the smooth flat plate surface and riblet effect on this process
- 2010
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Ingår i: Journal of Visualization. - : Springer Science and Business Media LLC. - 1343-8875 .- 1386-6478 .- 1875-8975. ; 13:2, s. 151-158
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Tidskriftsartikel (refereegranskat)abstract
- Evolution of the Lambda-vortex and its transformation into the turbulent spot in a flat plate boundary layer are investigated experimentally. Extensive measurements visualizing the Lambda-structure transformation into the turbulent spot on the smooth and ribbed surfaces of the flat plate are presented. The flow behavior in the course of spatial evolution of the Lambda-structure and turbulent spot is discussed. Specific features of the downstream evolution of Lambda-structure and turbulent spot on the smooth and ribbed surfaces are demonstrated, such as suppression by riblets of the Lambda-vortex transformation into the turbulent spot, appearance of the coherent structures of Lambda-vortex within ensemble-averaged turbulent spot, and oblique waves generation both by the Lambda-vortex and turbulent spot.
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| 125. |
- Chernoray, Valery, 1975, et al.
(författare)
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Study of the incipient spot breakdown controlled by riblets
- 2011
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Ingår i: Progress in flight physics. Eds. Ph. Reijasse, D. Knight, M. Ivanov, and I. Lipatov EUCASS advances in aerospace sciences book ser. - 9782759806744 ; , s. 519-530
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 126. |
- Chernoray, Valery, 1975, et al.
(författare)
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Study of the Incipient Spot Breakdown Controlled by Riblets
- 2012
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Ingår i: EUCASS Book Series on Advances in Aerospace Sciences, Vol. 3, Progress in Flight Physics, [Edited by Ph. Reijasse, D. Knight, M. Ivanov, and I. Lipatov]. ; , s. 545-556
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 127. |
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| 128. |
- Chernoray, Valery, 1975, et al.
(författare)
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Study of the nonlinear instability of a longitudinal structure generated by a roughness element in the boundary layer of a straight wing
- 2007
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Ingår i: Thermophys. Aeromech.. - 1531-8699. ; 14:3, s. 343-358
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Tidskriftsartikel (refereegranskat)abstract
- The results of experimental study of a nonlinear varicose instability of the streaky structure generated by roughness element in unswept-wing boundary layer are presented. Features of the varicose breakdown of longitudinal steady streaky structure such as modulation of structure in transverse and streamwise directions by secondary disturbance, occurrence of the new streaky structures and Lambda-structures downstream are shown. Spatio-temporal pictures of the hot-wire visualization of flow during spatial evolution of the streaky structures under influence of secondary high-frequency disturbance are discussed. Features of the adverse pressure gradient influence upon processes of the nonlinear varicose instability evolution and flow structure are revealed. Essential influence of the adverse pressure gradient on evolution of disturbances is shown. Comparison of varicose instability of the streaky structures generated in two different ways (the roughness element as in the given work, and continuous air blowing as in the earlier published work) is the carried out.
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| 129. |
- Domeika, Marius, et al.
(författare)
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Laboratory diagnostics for non-viral sexually transmitted infections in St. Petersburg, Russia : current situation and hallmarks for improvements
- 2008
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Ingår i: Journal of the European Academy of Dermatology and Venereology. - : Wiley. - 0926-9959 .- 1468-3083. ; 22:9, s. 1094-100
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The numbers and performance characteristics of laboratories providing sexually transmitted infection (STI) diagnostic services, as well as the rates of morbidity due to STIs in St. Petersburg, Russia, remain largely unknown. OBJECTIVE: The aim of the present study was to evaluate the range, quality and availability of diagnostic services for several non-viral STIs (Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum and Trichomonas vaginalis) in St. Petersburg during the period September 2005 to June 2006. METHODS: Survey data focusing on organization and performance characteristics of STI diagnostic services were assessed using questionnaires, telephone interviews and site visits. RESULTS: A total of 118 laboratories providing STI diagnostic services were identified. Of the surveyed laboratories, 54% (64 of 118) diagnosed syphilis, 81% (96 of 118) gonorrhoea, 80% (94 of 118) trichomoniasis and 49% (58 of 118) chlamydial infections. Although most of the laboratories could provide a presumptive diagnosis for syphilis, most of the N. gonorrhoeae and T. vaginalis testing of women did not adhere to international recommendations. Of the laboratories with the capacity to diagnose C. trachomatis infection, 69% still used serological testing (enzyme-linked immunosorbent assay) to detect antibodies to C. trachomatis. CONCLUSIONS: Overall, the diagnostic methods used to establish a laboratory diagnosis, the system of case reporting, the training of laboratory personnel and the level of interlaboratory communication clearly require improvement. This study represents the first step in a process of evaluation of the laboratory support for STI services and the establishment of an interlaboratory network in St. Petersburg.
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| 130. |
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