Hydrodynamics and oxygen transfer in a novel extra-loop fluidized bed bioreactor     

陆永生  胡龙兴 《上海大学学报(英文版)》2010,14(4):266-274

In this paper, the characteristics of fluid mixing time in a novel extra-loop fluidized bed were studied. The results showed that the mixing time was shortened with the increase of fluid velocity. All the discrete numbers of the reactor were above 0.2. The serial number n was 2.5 -3.0. It was judged accordingly that the reactor fluid state was continous stirred tank reactor （CSTR） mainly. When the inspiratory capacity increased the mixing time of the reactor was shortened. Thus the air input was beneficial for the fluid mixing. During the three phases mixing process, the mixing time of the reactor could be decreased by the n increase of carrier and air loading together, but the change was not significant. The parameters affecting the reactor fluid state were fluid velocity, inspiratory capacity and carrier. KLa could be increased with the air loading increase, and at the same gas/liquid ratio when the pressure drop was high, KL~ value was increased. The amount of carrier complex influence on KLa. As the carrier loading continued to increase, its value had been dropped but the changes was not significant, and optimization condition was found at above 800 1 000 g carrier loading （pouzzolane） or 600 g PVC. Under gas/liquid ratio of 0.8% -5.2%, KLa was （0.62-1.37）×10^-2· s^-1.  相似文献   

Poly(vinyl alcohol)-heparin biosynthetic microspheres produced by microfluidics and ultraviolet photopolymerisation     

Cara Young  Kester Rozario  Christophe Serra  Laura Poole-Warren  Penny Martens 《Biomicrofluidics》2013,7(4)

Biosynthetic microspheres have the potential to address some of the limitations in cell microencapsulation; however, the generation of biosynthetic hydrogel microspheres has not been investigated or applied to cell encapsulation. Droplet microfluidics has the potential to produce more uniform microspheres under conditions compatible with cell encapsulation. Therefore, the aim of this study was to understand the effect of process parameters on biosynthetic microsphere formation, size, and morphology with a co-flow microfluidic method. Poly(vinyl alcohol) (PVA), a synthetic hydrogel and heparin, a glycosaminoglycan were chosen as the hydrogels for this study. A capillary-based microfluidic droplet generation device was used, and by varying the flow rates of both the polymer and oil phases, the viscosity of the continuous oil phase, and the interfacial surface tension, monodisperse spheres were produced from ∼200 to 800 μm. The size and morphology were unaffected by the addition of heparin. The modulus of spheres was 397 and 335 kPa for PVA and PVA/heparin, respectively, and this was not different from the bulk gel modulus (312 and 365 for PVA and PVA/heparin, respectively). Mammalian cells encapsulated in the spheres had over 90% viability after 24 h in both PVA and PVA/heparin microspheres. After 28 days, viability was still over 90% for PVA-heparin spheres and was significantly higher than in PVA only spheres. The use of biosynthetic hydrogels with microfluidic and UV polymerisation methods offers an improved approach to long-term cell encapsulation.  相似文献   

Analysing expertise through data mining: an example based on treading water     

Christophe Schnitzler  Chris Button  Ludovic Seifert  James Croft 《Journal of sports sciences》2013,31(12):1186-1195

Abstract

A classification system of treading water based on a conceptual typology was first established and then verified empirically. The typology was established on two concepts: the nature of the forces created within the water and the type of inter-limb coordination used. Thirty-eight participants were videotaped while treading water. Multivariate statistics were used to understand how the different behavioural types related to expertise. Three distinct groups of coordination patterns were adopted during treading water. A support vector machine procedure was used as a confirmatory procedure. The data mining process provides a methodological framework to analyse expertise in sports activities, and in this context suggests that a taxonomy can be established among the numerous coordination solutions that allow humans to create stabilising forces in the water.  相似文献   

Sleep restriction and degraded reaction-time performance in Figaro solo sailing races     

RÉmy Hurdiel  HANS P.A. Van Dongen  Christophe Aron  Peter McCauley  Laure Jacolot  Denis Theunynck 《Journal of sports sciences》2013,31(2):172-174

Abstract

In solo offshore sailing races like those of the Solitaire du Figaro, sleep must be obtained in multiple short bouts to maintain competitive performance and safety. Little is known about the amount of sleep restriction experienced at sea and the effects that fatigue from sleep loss have on sailors’ performance. Therefore, we assessed sleep in sailors of yachts in the Figaro 2 Beneteau class during races and compared response times on a serial simple reaction-time test before and after races. Twelve men (professional sailors) recorded their sleep and measured their response times during one of the three single-handed races of 150, 300 and 350 nautical miles (nominally 24–50 h in duration). Total estimated sleep duration at sea indicated considerable sleep insufficiency. Response times were slower after races than before. The results suggest that professional sailors incur severe sleep loss and demonstrate marked performance impairment when competing in one- to two-day solo sailing races. Competitive performance could be improved by actively managing sleep during solo offshore sailing races.  相似文献   

Situational Indexes of Achievement Motivation,Help-Seeking,and Performance: Influences of the Learning Context and Gender Differences     

Christophe Gernigon  Fabienne D'arripe-Longueville  Véronique Debove  Aude Puvis 《Research quarterly for exercise and sport》2013,84(4):473-479

Abstract

Sixteen college athletes and non-athletes were given 10 30-sec. practice trials to learn how to balance on a stabilometer. The next day they were allowed three more trials alone and three trials before a group of spectators. The non-athletes were significantly better on two of the three trials performed in front of the spectators. They also performed better than the athletes throughout the ten practice trials, although the tenth and last trial approached but did not yield a significant difference at the .05 level.  相似文献   

The Cartographic Eye in Children’s Picturebooks: Between Maps and Narratives     

Christophe Meunier 《Children‘s Literature in Education》2017,48(1):21-38

This article examines the place occupied by maps in children’s picturebooks. After a brief overview of the different roles that are assigned to maps in children’s books, the article considers five French picturebooks—Warja Lavater’s Le petit chaperon rouge (1965), Olivier Douzou and Isabelle Simon’s L’autobus numéro 33 (1996), Véronique Vernette’s Cocorico poulet Piga (1999), Rebecca Dautremer and Arthur Leboeuf’s Le loup de la 135 ^ème (2008) and Kochka and Fabienne Cinquin’s Dans ma ville, il y a… (2011)—in order to focus on how the narrative, whether enclosed, superimposed or linked to the text in some other way, is evoked by the geographic shape of the maps. It is argued that the particular use and function of a map depends on its shape or placement in a book, distinguishing between the incorporation of maps only as a significant picture (its use) from the subject within the whole narrative (its function). Thus the article articulates what uses a map can have within a narrative. It also explores the mechanics of the iconotext, showing that a cartographic picture fulfils a precise, rather than a general, function of spatialisation. Hence three main functions of spatialisation in maps and mapping are distinguished, whereby an author could use maps to help a character discover, conquer, or organise a space.  相似文献   

Multilevel Mediation: Cumulative Contextual Risk,Maternal Differential Treatment,and Children's Behavior Within Families     

Jean Christophe Meunier  Michael Boyle  Thomas G. O'Connor  Jennifer M. Jenkins 《Child development》2013,84(5):1594-1615

This study tests the hypothesis that links between contextual risk and children's outcomes are partially explained by differential parenting. Using multi‐informant measurement and including up to four children per family (M_age = 3.51, SD = 2.38) in a sample of 397 families, indirect effects (through maternal differential parenting: self‐reported and observed) of cumulative contextual risk on four child outcomes were investigated. Cumulative risk was associated with higher levels of differential parenting and, in turn, with higher levels of behavioral problems. Indirect effects were strongest for attentional and social problems but also evident for aggression. The link between differential parenting and outcome was moderated by favoritism, but this was only evident for maternal report and strongest for aggression.  相似文献   

Shoe drop reduction influences the lower limb biomechanics of children tennis players during an open stance forehand: A longitudinal study     

Alexis Herbaut  Emilie Simoneau-Buessinger  Franck Barbier  Christophe Gillet  Maxime Roux  Nils Guéguen 《European Journal of Sport Science》2017,17(10):1261-1269

Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8?mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (?73%, p?=?.005) but increased peak ankle plantarflexors moment (+47%, p?=?.050) and peak ankle power absorption (+107%, p?=?.005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces.  相似文献   

Europalia.China Concludes with Great Success     

Christophe Pourtois  Marcelle Rabinowicz 《中外文化交流(英文版)》2010,(4):4-9

<正>Europalia is a major international arts festival held every other year to celebrate one invited country's cultural heritage. Founded in 1969, this biennial festival is celebrated in  相似文献   

Toward the identification and role of structural variations during dog domestication     

Christophe Hitte 《国家科学评论(英文版)》2019,6(1):123

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