• 제목/요약/키워드: Oxford University

검색결과 221건 처리시간 0.024초

Fouling and cleaning of a tubular ultrafiltration ceramic membrane

  • Siddiqui, Farrukh Arsalan;Field, Robert W.
    • Membrane and Water Treatment
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    • 제7권5호
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    • pp.433-449
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    • 2016

  • The successful application of cleaning protocols is vital for optimized filtration processes. A series of experiments with an ultrafiltration ceramic tubular membrane were carried out for the foulants dextran and carboxymethyl cellulose. Firstly, the impact on fouling of concentration changes was investigated with the increase in resistance being used as the key parameter. In the second phase, removal of reversible fouling was also investigated by employing intermittent rinsing consisting of a cold water rinse followed by a hot one. A comparative analysis for both foulants is reported. Across a range of concentrations and for both foulants, the reduction in resistance due to rinsing was found to depend upon concentration (C); it changed as $C^n$ where n was found to be 0.3. A plausible semi-theoretical explanation is given. Thirdly, for both foulants, the application of a combination of strong alkaline solutions with oxidizing agent (mainly sodium hypochlorite) followed by acid was found to be appropriate for cleaning of the ceramic membrane. The effect of increased temperature for cleaning agents followed by a warm water rinse contributed positively to the cleaning capability.

  • https://doi.org/10.12989/mwt.2016.7.5.433 인용 KSCI

Sway buckling of down-aisle, spliced, unbraced pallet rack structures

  • Beale, R.G.;Godley, M.H.R.
    • Steel and Composite Structures
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    • 제3권5호
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    • pp.307-320
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    • 2003

  • This paper presents an efficient approach to the determination of the buckling loads of down-aisle, spliced, unbraced, pallet rack structures subjected to vertical and horizontal loads. A pallet rack structures is analysed by considering the stability equations of an equivalent free-sway column. The effects of semi-rigid beam-to-upright, splice-to-upright and base-plate-to-upright connections are fully incorporated into the analysis. Each section of upright between successive beam levels in the pallet rack is considered to be a single column element with two rotational degrees of freedom. A computer algebra package was used to determine modified stability equations for column elements containing splices. The influence of the position of splices in a pallet rack is clearly demonstrated.

  • https://doi.org/10.12989/scs.2003.3.5.307 인용

Kinematic Analysis of Head and Trunk Movements of Young Adults while Climbing Stairs or a Ramp

  • Han, Jin-Tae
    • The Journal of Korean Physical Therapy
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    • 제22권6호
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    • pp.21-28
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    • 2010

  • Purpose: The purpose of this study was to investigate the kinematic adaptation of head and trunk to ascend stairs and a ramp. Subjects were healthy young adults. Three-dimensional kinematic patterns of head and trunk movements were examined during stair climbing and steeper ramp climbing. Methods: Fourteen young subjects with no history of chronic or acute musculoskeletal, cardiovascular or respiratory disorders took part in this experiment. Kinematic data were collected using a 6 camera Vicon system (Oxford Metrix, Oxford, England). Repeated measures ANOVA analyses were used to investigate the effect of gait mode on kinematics of the head and trunk. Results: The angle of the trunk while ascending stairs or a ramp was modified in three human planes (p<0.05). The angle of head and neck during the ascending of stairs or a ramp was not changed in the sagittal plane but was changed in the frontal and transverse planes (p<0.05). Conclusion: This study describes and discusses some basic kinematic mechanisms underlying the pattern of head and trunk changes during stair and ramp climbing and showed that postural adaptation of the head and trunk is necessary to maintain balance.

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LOCALLY ENRICHED QUADTREE GRID NUMERICAL MODEL FOR NEARSHORE CIRCULATION IN THE SURF ZONE

  • Park, Koo-Yong
    • Water Engineering Research
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    • 제1권3호
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    • pp.187-197
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    • 2000

  • This paper describes an adaptive quadtree-based 2DH wave-current interaction model which is able to predict wave breaking, shoaling, refraction, diffraction, wave-current interaction, set-up and set-down, mixing processes (turbulent diffusion), bottom frictional effects, and movement of the land-water interface at the shoreline. The wave period-and depth-averaged governing equations are discretised explictly by means of an Adams-Bashforth second-order finite difference technaique on adaptive hierarchical staggered quadtree grids. Grid adaptation is achieved through seeding points distributed according to flow criteria(e.g. local current gradients). Results are presented for nearshore circulation at a sinusoidal beach. Enrichment permits refined modelling of important localised flow features.

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