The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform
Robert M. Clark - One of the best experts on this subject based on the ideXlab platform.
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removal of cryptosporidium parvum oocysts by rapid sand filtration with ballasted flocculation filtration and intermediate Downwashes
Acta Hydrochimica Et Hydrobiologica, 2005Co-Authors: Vitaly Gitis, Viatcheslav Freger, Roy C. Haugth, Robert M. ClarkAbstract:A novel and efficient protocol optimising deep-bed filtration of surface water was developed. The innovation lies in ballasted-flocculation filtration and an intermediate downwash. The approach is based on the assumption that kaolin particles with a partial positive charge may adsorb onto the surface of C. parvum oocysts and neutralize their negative charge. Application of this technology enhanced removal of inorganic particles and Cryptosporidium parvum oocysts by approximately 30 % and shortened the ripening stage of the filtration process from 1 h to about 10 min. Entfernung von Cryptosporidium parvum-Oozysten mit Hilfe der Schnellsandfiltration: Flockungsfiltration mit dotierter partikularer Grundbelastung und zwischengeschalteten Spulungen im Abstrom Eine neuartiges Verfahren zur Tiefenfiltration von Oberflachenwasser wird vorgestellt, das mit dem Zusatz von Kaolin bei der Flockungsfiltration und zwischengeschalteten Spulschritten im Abstrom arbeitet. Das Verfahren basiert auf der Annahme, dass die Kaolinpartikel mit ihren positiven Teilbereichen auf der Oberflache der CryptosporidiumOozysten sorbieren und deren negative Oberflachenladung neutralisieren. Durch die Anwendung dieser Technologie wurde die Entfernung von Cryptosporidium parvum-Oozysten um etwa 30 % verbessert und der Zeitraum fur die Filterreifung von 1 h auf 10 min verkurzt.
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Removal of Cryptosporidium parvum Oocysts by Rapid Sand Filtration with Ballasted Flocculation‐Filtration and Intermediate Downwashes
Acta hydrochimica et hydrobiologica, 2005Co-Authors: Vitaly Gitis, Viatcheslav Freger, Roy C. Haugth, Robert M. ClarkAbstract:A novel and efficient protocol optimising deep-bed filtration of surface water was developed. The innovation lies in ballasted-flocculation filtration and an intermediate downwash. The approach is based on the assumption that kaolin particles with a partial positive charge may adsorb onto the surface of C. parvum oocysts and neutralize their negative charge. Application of this technology enhanced removal of inorganic particles and Cryptosporidium parvum oocysts by approximately 30 % and shortened the ripening stage of the filtration process from 1 h to about 10 min. Entfernung von Cryptosporidium parvum-Oozysten mit Hilfe der Schnellsandfiltration: Flockungsfiltration mit dotierter partikularer Grundbelastung und zwischengeschalteten Spulungen im Abstrom Eine neuartiges Verfahren zur Tiefenfiltration von Oberflachenwasser wird vorgestellt, das mit dem Zusatz von Kaolin bei der Flockungsfiltration und zwischengeschalteten Spulschritten im Abstrom arbeitet. Das Verfahren basiert auf der Annahme, dass die Kaolinpartikel mit ihren positiven Teilbereichen auf der Oberflache der CryptosporidiumOozysten sorbieren und deren negative Oberflachenladung neutralisieren. Durch die Anwendung dieser Technologie wurde die Entfernung von Cryptosporidium parvum-Oozysten um etwa 30 % verbessert und der Zeitraum fur die Filterreifung von 1 h auf 10 min verkurzt.
Jae-hung Han - One of the best experts on this subject based on the ideXlab platform.
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The advance ratio effect on the lift augmentations of an insect-like flapping wing in forward flight
Journal of Fluid Mechanics, 2016Co-Authors: Jong-seob Han, Jo Won Chang, Jae-hung HanAbstract:Time-varying force/moment measurements and digital particle image velocimetry (DPIV) were conducted to reveal the influence of an advance ratio $J$ on an insect-like flapping wing. A scaled-up robotic model and a servo-driven towing tank were employed to investigate nine individual $J$ cases – $J=0$ (hovering), 0.0625, 0.1250, 0.1875, 0.25, 0.50, 0.75, 1.0 and $\infty$ (gliding motion) – at a high Reynolds number ($Re\sim 10^{4}$). At $J\leqslant 0.25$, the aerodynamic forces slightly increased from those in hover ($J=0$). The centres of pressure in these cases were concentrated in the outboard section, and the leading-edge vortices (LEVs) grew more conically than those in hover. Spanwise cross-sectional DPIV indicated that the wings generated more balanced Downwashes, which effectively supported the slight lift increments in this range. At $J>0.25$, a drastic force drop appeared as $J$ increased. The DPIV results in the $J=0.5$ case clearly showed a strong trailing-edge vortex on the outboard trailing edges encroaching into the upper surface, which had been occupied by the LEV for lower $J$. The LEV vorticity was noticeably weakened, and coherent substructures with substantial turbulence accompanied this vorticity. In the $J=1.0$ case, such encroachment was extended to 50 % of the section, and the LEV outboard became significantly irregular. The near-wake structures also showed that the $J=1.0$ case had the narrowest downwash area, with unstable root and tip vortices, which reflected considerable attenuation in the lift enhancements. It was of note that all of these vortical behaviours were clearly distinguishable from aspect ratio ($AR$) effects. The $J$ even played a similar role to that of the $AR$ in the Navier–Stokes equation. These findings clearly indicated that the $J$ could be an independent quantity governing the overall vortical system and lift enhancing mechanism on a flapping wing of a flapping-wing micro air vehicle.
Vitaly Gitis - One of the best experts on this subject based on the ideXlab platform.
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removal of cryptosporidium parvum oocysts by rapid sand filtration with ballasted flocculation filtration and intermediate Downwashes
Acta Hydrochimica Et Hydrobiologica, 2005Co-Authors: Vitaly Gitis, Viatcheslav Freger, Roy C. Haugth, Robert M. ClarkAbstract:A novel and efficient protocol optimising deep-bed filtration of surface water was developed. The innovation lies in ballasted-flocculation filtration and an intermediate downwash. The approach is based on the assumption that kaolin particles with a partial positive charge may adsorb onto the surface of C. parvum oocysts and neutralize their negative charge. Application of this technology enhanced removal of inorganic particles and Cryptosporidium parvum oocysts by approximately 30 % and shortened the ripening stage of the filtration process from 1 h to about 10 min. Entfernung von Cryptosporidium parvum-Oozysten mit Hilfe der Schnellsandfiltration: Flockungsfiltration mit dotierter partikularer Grundbelastung und zwischengeschalteten Spulungen im Abstrom Eine neuartiges Verfahren zur Tiefenfiltration von Oberflachenwasser wird vorgestellt, das mit dem Zusatz von Kaolin bei der Flockungsfiltration und zwischengeschalteten Spulschritten im Abstrom arbeitet. Das Verfahren basiert auf der Annahme, dass die Kaolinpartikel mit ihren positiven Teilbereichen auf der Oberflache der CryptosporidiumOozysten sorbieren und deren negative Oberflachenladung neutralisieren. Durch die Anwendung dieser Technologie wurde die Entfernung von Cryptosporidium parvum-Oozysten um etwa 30 % verbessert und der Zeitraum fur die Filterreifung von 1 h auf 10 min verkurzt.
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Removal of Cryptosporidium parvum Oocysts by Rapid Sand Filtration with Ballasted Flocculation‐Filtration and Intermediate Downwashes
Acta hydrochimica et hydrobiologica, 2005Co-Authors: Vitaly Gitis, Viatcheslav Freger, Roy C. Haugth, Robert M. ClarkAbstract:A novel and efficient protocol optimising deep-bed filtration of surface water was developed. The innovation lies in ballasted-flocculation filtration and an intermediate downwash. The approach is based on the assumption that kaolin particles with a partial positive charge may adsorb onto the surface of C. parvum oocysts and neutralize their negative charge. Application of this technology enhanced removal of inorganic particles and Cryptosporidium parvum oocysts by approximately 30 % and shortened the ripening stage of the filtration process from 1 h to about 10 min. Entfernung von Cryptosporidium parvum-Oozysten mit Hilfe der Schnellsandfiltration: Flockungsfiltration mit dotierter partikularer Grundbelastung und zwischengeschalteten Spulungen im Abstrom Eine neuartiges Verfahren zur Tiefenfiltration von Oberflachenwasser wird vorgestellt, das mit dem Zusatz von Kaolin bei der Flockungsfiltration und zwischengeschalteten Spulschritten im Abstrom arbeitet. Das Verfahren basiert auf der Annahme, dass die Kaolinpartikel mit ihren positiven Teilbereichen auf der Oberflache der CryptosporidiumOozysten sorbieren und deren negative Oberflachenladung neutralisieren. Durch die Anwendung dieser Technologie wurde die Entfernung von Cryptosporidium parvum-Oozysten um etwa 30 % verbessert und der Zeitraum fur die Filterreifung von 1 h auf 10 min verkurzt.
R. L. Bristol - One of the best experts on this subject based on the ideXlab platform.
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Wake Alleviation Properties of Triangular-Flapped Wings
2015Co-Authors: Jason M. Ortega, R. L. BristolAbstract:The wake alleviation properties of wings with outboard, triangular ap extensions are estimated using data from particle image velocimetry. The experiments are conducted in a towing tank at chord-based Reynolds numbers of O (105). The triangular- apped wings generate two unequal strength, counter-rotating vortex pairs that have circulation strength ratios ranging from ¡ 0.4 to ¡ 0.7. Introducing the oppositely signed ap vortices near the tip vortices causes a rapidly growing instability to occur between the vortices on either side of the wake. The resulting nonlinear interactions between the vortices result in a wake that is highly three-dimensional and incoherent. These effects are re ected in amarked decrease in both the rolling moment and downwash on a simulated following wing. To determine the wake alleviation properties of the triangular- apped wings, their wakes are compared to that of a conventional, rectangular wing. For all of the experimental runs, the wakes of the triangular- apped wings have maximum rolling moments and Downwashes that are substantially less than those of the rectangular wing. The results indicate that the instability in the wake of the triangular- apped wings offers a possible mechanism to reduce signi cantly the wake hazard problem. I
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Wake Alleviation Properties of Triangular-Flapped Wings
AIAA Journal, 2002Co-Authors: Jason M. Ortega, R. L. Bristol, Omer SavasAbstract:Thewakealleviationproperties of wingswith outboard, triangulareapextensionsareestimated usingdatafrom particle image velocimetry. The experiments are conducted in a towing tank at chord-based Reynolds numbers of O O(10 5). The triangular-eapped wings generate two unequal strength, counter-rotating vortex pairs that have circulation strength ratios ranging from i 0.4 to i 0.7. Introducing the oppositely signed eap vortices near the tip vortices causes arapidly growing instability to occur between the vortices on either side of the wake. The resulting nonlinear interactionsbetween thevorticesresult inawake that ishighly three-dimensional and incoherent. These effectsarereeected inamarked decreaseinboth therollingmoment and downwash on asimulated followingwing. To determine the wake alleviation properties of the triangular-eapped wings, their wakes are compared to that of a conventional, rectangular wing. For all of the experimental runs, the wakes of the triangular-eapped wings have maximum rolling moments and Downwashes that are substantially less than those of the rectangular wing. The results indicate that the instability in the wake of the triangular-e apped wings offers a possible mechanism to reduce signie cantly the wake hazard problem.
Jason M. Ortega - One of the best experts on this subject based on the ideXlab platform.
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Wake Alleviation Properties of Triangular-Flapped Wings
2015Co-Authors: Jason M. Ortega, R. L. BristolAbstract:The wake alleviation properties of wings with outboard, triangular ap extensions are estimated using data from particle image velocimetry. The experiments are conducted in a towing tank at chord-based Reynolds numbers of O (105). The triangular- apped wings generate two unequal strength, counter-rotating vortex pairs that have circulation strength ratios ranging from ¡ 0.4 to ¡ 0.7. Introducing the oppositely signed ap vortices near the tip vortices causes a rapidly growing instability to occur between the vortices on either side of the wake. The resulting nonlinear interactions between the vortices result in a wake that is highly three-dimensional and incoherent. These effects are re ected in amarked decrease in both the rolling moment and downwash on a simulated following wing. To determine the wake alleviation properties of the triangular- apped wings, their wakes are compared to that of a conventional, rectangular wing. For all of the experimental runs, the wakes of the triangular- apped wings have maximum rolling moments and Downwashes that are substantially less than those of the rectangular wing. The results indicate that the instability in the wake of the triangular- apped wings offers a possible mechanism to reduce signi cantly the wake hazard problem. I
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Wake Alleviation Properties of Triangular-Flapped Wings
AIAA Journal, 2002Co-Authors: Jason M. Ortega, R. L. Bristol, Omer SavasAbstract:Thewakealleviationproperties of wingswith outboard, triangulareapextensionsareestimated usingdatafrom particle image velocimetry. The experiments are conducted in a towing tank at chord-based Reynolds numbers of O O(10 5). The triangular-eapped wings generate two unequal strength, counter-rotating vortex pairs that have circulation strength ratios ranging from i 0.4 to i 0.7. Introducing the oppositely signed eap vortices near the tip vortices causes arapidly growing instability to occur between the vortices on either side of the wake. The resulting nonlinear interactionsbetween thevorticesresult inawake that ishighly three-dimensional and incoherent. These effectsarereeected inamarked decreaseinboth therollingmoment and downwash on asimulated followingwing. To determine the wake alleviation properties of the triangular-eapped wings, their wakes are compared to that of a conventional, rectangular wing. For all of the experimental runs, the wakes of the triangular-eapped wings have maximum rolling moments and Downwashes that are substantially less than those of the rectangular wing. The results indicate that the instability in the wake of the triangular-e apped wings offers a possible mechanism to reduce signie cantly the wake hazard problem.