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Experimental Investigation of Spoiler Deployment on Wing Stall

Open journal of Fluid Dynamics 2018年第3期8卷 308-320页

作者： scott Douglas Lindsay paul Walsh Ryerson University Toronto Canada

Upper surface wing flaps, known as spoiler, are typically used to reduce lift and increase drag at touchdown;however spoilers have been shown to increase lift and reduce drag at near-stall conditions. The purpose of this experiment was to determine the spoilers’ impact on lift, drag, moment, and aerodynamic efficiency of a NACA 2412 airfoil at angles of attack (α) from −8 ° to 32 °. The experiment was conducted in the Ryerson Low-Speed Wind Tunnel (closed-circuit, 1 m × 1 m test section) at Re=783761, Ma=0.136. The lift coefficient (Cl), drag coefficient (Cd), moment coefficient about the quarter-chord () were captured with a changing spoiler deflection angle (δ) and spoiler length (b in percent chord). It was found that deflecting the spoiler resulted in an increase maximum lift of up to 2.497%. It was found that deflecting the spoiler by 8° was optimal for the b=10 cases. Any larger deflection reduced the lift gain, and a deflection of 25° caused the maximum lift to be 2.786% less than the clean configuration. In the b=15 case, δ=15° was optimal (1.760% maximum lift coefficient increase). The b=10 cases increased maximum lift coefficient between 0.35% and 2.10% higher than the b=15 cases. The source of the lift gain at high angles of attack is apparent in an analysis of the airfoil pressure distribution. The spoiler increased the suction peak on the airfoil surface upstream of the spoiler, and increased the pressure downstream. However the suction increase upstream is larger than the pressure increase downstream, resulting in a net increase in lift. The spoiler increased the stall angle 37.658% to 87.658% higher than the clean configuration. Stall angle increased with both δ and with an increased spoiler length. The spoiler airfoil produced less drag than the clean configuration at high angles of attack. The combination of the increased lift, and reduced drag resulted in an increase in aerodynamic efficiency at high angle of attack.

关键词： Aircraft Stall Wind-Tunnel Spoilers Low-Speed Aerodynamics

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Stress, hippocampal neurogenesis and cognition： functional correlations

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Frontiers in Biology 2016年第3期11卷 182-192页

作者： paul j. Lucassen Charlotte A. Oomen Centre for Neuroscienee Swammerdam Institute for Life Sciences University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands Department of Molecular and Cellular Neurobiology Center for Neurogenomics and Cognitive ResearchNeuroscience Campus Amsterdam VU University Amsterdam De Boelelaan 1085 1081 HV Amsterdam The Netherlands

The brain of many species including humans, harbors stem cells that continue to generate new neurons up into adulthood. This form of structural plasticity occurs in a limited number of brain regions, i.e. the subventricular zone and the hippocampal dentate gyrus and is regulated by environmental and hormonal factors. In this minireview, we provide an overview of the effects of stress and glucocorticoid hormones on adult hippocampal neurogenesis and discuss how these effects may be relevant for cognitive function and possibly, brain disease. While its exact functional role remains elusive, adult neurogenesis has been implicated in learning and memory, fear and mood regulation and recently, adult-born neurons were found to be involved in specific cognitive functions such as pattern separation （i.e. the ability to form unique memory representations） and cognitive flexibility. The process of adult neurogenesis is influenced by several factors; whereas e.g. exercise stimulates, exposure to stress and stress hormones generally inhibit neurogenesis. Effects of acute, mild stress are generally short-lasting and recover quickly, but chronic or severe forms of stress can induce lasting reductions in adult neurogenesis. Some of the inhibitory effects of stress can be rescued by exercise, by allowing a period of recovery from stress, by drugs that target the stress system, or by some, but not all, antidepressants. Stress may, partly through its effects on adult neurogenesis, alter structure and plasticity of the hippocampal circuit. This can lead to subsequent changes in stress responsivity and aspects of memory processing, which may be particularly relevant for stress related psychopathology or brain diseases that involve perturbed memory processing.

关键词： adult neurogenesis stem cells hippocampus stress memory pattern separation cognition

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Vibration induced flow in hoppers:DEM 2D polygon model

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Particuology 2008年第6期6卷 455-466页

作者： Feras Y. Fraige paul A. Langston Andrew j. Matchett john Dodds Faculty of Mining and Environmental Engineering Al-Hussein Bin Talal University Jordan Chemical and Environmental Engineering Nottingham University University Park Chemical Engineering University of Teesside Centre RAPSODEE Ecole Des Mines

A two-dimensional discrete element model （DEM） simulation of cohesive polygonal particles has been developed to assess the benefit of point source vibration to induce flow in wedge-shaped hoppers. The particle-particle interaction model used is based on a multi-contact principle. The first part of the study investigated particle discharge under gravity without vibration to determine the critical orifice size （Bc） to just sustain flow as a function of particle shape. It is shown that polygonal-shaped particles need a larger orifice than circular particles. It is also shown that Bc decreases as the number of particle vertices increases. Addition of circular particles promotes flow of polygons in a linear manner. The second part of the study showed that vibration could enhance flow, effectively reducing Bc. The model demonstrated the importance of vibrator location （height）, consistent with previous continuum model results, and vibration amplitude in enhancing flow.

关键词： Bulk solids Vibration DEM Hoppers Materials handling Polygon

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Measurement of in-plane deformations of microsystems by digital holography and speckle interferometry(Invited Paper)

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Chinese Optics Letters 2009年第12期7卷 1109-1112页

作者： G. Pedrini j. Gaspar O. paul W. Osten Institut fr Technische Optik Universitt Stuttgart Department of Microsystems Engineering-IMTEK Universitt Freiburg

The reliability of microsystems is an important issue and for their quality inspection, it is necessary to know the displacements or deformations due to the applied mechanical, thermal, or electrostatic loads. We show how interferometrical techniques like digital holography and speckle interferometry can be used for the measurement of in plane deformations of microsystems with nanometric accuracy and we give a description of the measurement uncertainties.

关键词： Invited Paper Measurement of in-plane deformations of microsystems by digital holography and speckle interferometry

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How Do Sugars Regulate Plant Growth and Development？ New Insight into the Role of Treha Iose-6-Phosphate

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Molecular Plant 2013年第2期6卷 261-274页

作者： Liam E. O'Hara Matthew j. paul Astrid Wingler Genetics Evolution and Environment University College London Gower Street London WCl E 6BT UK Plant Science Rothamsted Research Harpenden Hertfordshire AL5 2JQ UK

Plant growth and development are tightly controlled in response to environmental conditions that influence the availability of photosynthetic carbon in the form of sucrose. Trehalose-6-phosphate （T6P）, the precursor of trehalose in the biosynthetic pathway, is an important signaling metabolite that is involved in the regulation of plant growth and development in response to carbon availability. In addition to the plant＇s own pathway for trehalose synthesis, formation of T6P or trehalose by pathogens can result in the reprogramming of plant metabolism and development. Developmental processes that are regulated by T6P range from embryo development to leaf senescence. Some of these processes are regulated in interaction with phytohormones, such as auxin. A key interacting factor of T6P signaling in response to the environment is the protein kinase sucrose non-fermenting related kinase-1 （SnRK1）, whose catalytic activity is inhibited by T6R SnRK1 is most likely involved in the adjustment of metabolism and growth in response to starvation. The transcription factor bZlP11 has recently been identified as a new player in the T6P/SnRK1 regulatory pathway. By inhibiting SnRK1, T6P promotes biosynthetic reactions. This regulation has important consequences for crop production, for example, in the developing wheat grain and during the growth of potato tubers.

关键词： bZlP11 carbon availability plant development starvation sucrose non-fermenting related kinase-1 (SnRK1) trehalose trehalose-6-phosphate.

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Prospects for the continued development of environmentally-realistic toxicity test susing microorganisms

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journal of Environmental Sciences 1993年第3期5卷 253-268页

作者： john Cairns,jr. paul V.McCormick scott E.Belanger Department of Biology and University Center for Environmental and Hazardous Materials Studies Virginia Polytechnic Institute and State UniversityBlacksburgVirginia 24061-0415U.S.A. Department of Biology Elizabethtown CollegeElizabethtownPennsylvania-17022-2298U.S.A.and Senior Research AssociateUniversity Center for Environmental and Hazardous Materials StudiesVirginia Polytechnic Institute and State UniversityBlacksburgVirginia-24061-0415U.S.A. Stream Ecosystem Research Section Environmental Safety DepartmentThe Procter and Gamble CompanyCincinnatiOhio-45217U.S.A.

The focus of environmental regulations has changed significantly since the introduction of the bioassay as a standard means of assessing environmental *** in this change is an increasing emphasis on protecting the integrity of natural ecosystems,which incorporate community-and system-level properties as well as organismal and population ***,support for the use of multispecies testing has widened to include not only ecologists in academia but environmental scientists in the regulatory and industrial sector as *** reason for this trend is clear:the additional environmental realism gained from tests utilizing communities of organisms allows for greater insight into the potential hazard of chemicals and other forms of human activity to natural ecosystems that cannot be obtained from single species tests *** of the problems cited for multispecies testing early in their evolution as a hazard assessment tool have been refuted or *** particular,the use of natural microbial communities minimizes several shortcomings typically associated with multispecies toxicity *** discussion includes the utility of microcosm and mesocosm tests using aquatic microbial communities as hazard assessment tools in conjunction with accumulating information on their performance in toxicity testing *** increasing body of experimental evidence supports an expansion in the use of these tests for a variety of regulatory and research purposes.A shift in research focus is needed,however,to answer remaining questions and further refine standard protocols for these valuable ecotoxicological tools.

关键词： environmentally-realistic toxicity tests microorganisms.

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Forkhead box protein P1, a key player in neuronal development?

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Neural Regeneration Research 2018年第5期13卷 801-802页

作者： Luca Braccioli Cora H.Nijboer paul j.Coffer Laboratory of Neuroimmunology and Developmental Origins of Disease (NIDOD) University Medical Center Utrecht University Regenerative Medicine Center University Medical Center Utrecht Utrecht University Center for Molecular Medicine and Division of Pediatrics University Medical Center Utrecht Utrecht University

Forkhead box protein P1（FOXP1）is a transcription factor belonging to the forkhead box（FOX）proteins,a family of transcriptional regulators sharing a highly conserved forkhead DNA-binding domain（Bacon and Rappold,2012）.Previous reports have proposed a role for FOXP1 in functionally regulating the central nervous system（CNS）,while mutations in FOXP1 have been implicated in cognitive abnormalities（Bacon and Rappold, 2012）.

关键词： a key player in neuronal development Forkhead box protein P1

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Mechanically durable,super-repellent 3D printed microcell/nanoparticle surfaces

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Nano Research 2022年第6期15卷 5678-5686页

作者： Sajad Haghanifar Anthony j Galante Mehdi Zarei jun Chen Susheng Tan paul W Leu Department of Industrial Engineering University of PittsburghPittsburghPA 15261USA Department of Mechanical Engineering and Materials Science University of PittsburghPittsburghPA 15261USA Department of Electrical and Computer Engineering and Peterson Institute of NanoScience and Engineering University of PittsburghPittsburghPA 15261USA Department of Chemical Engineering University of PittsburghPittsburghPA 15261USA

Three-dimensional(3D)printed re-entrant micropillars have demonstrated high static contact angles for an unprecedented variety of liquids,but have yet to achieve this with low contact angle hysteresis and excellent abrasion *** report on the demonstration of 3D printed microcell/nanoparticle structures that exhibit high static contact angle,low contact angle hysteresis,and high mechanical *** and microcells both exhibit high static contact angles with water and ethylene glycol(EG),but suffer from high contact angle hysteresis,indicative of rose petal *** modeling results indicate that micropillars are able to achieve higher static contact angle and breakthrough pressure simultaneously compared with ***,simulations also indicate that micropillars have higher maximum equivalent stress at their bases,so that they are more prone to mechanical *** address contact angle hysteresis and mechanical durability issues by the creation of 3D printed microcell/nanoparticle arrays that demonstrate super-repellency and retain their super-repellency after 100 cycles of mechanical abrasion with a Scotch-Brite abrasive pad under a pressure of 1.2 *** use of interconnected microcell structures as opposed to micropillars addresses mechanical durability *** contact angle hysteresis is realized by coating 3D printed structures with low surface energy nanoparticles,which lowers the solid–liquid contact area *** results demonstrate new 3D printed structures with mechanical durability and super-repellency through the use of microcell structures integrated with fluorinated nanoparticles.

关键词： superomniphobicity three-dimensional(3D)printing surface evolver mechanical durability microcell re-entrant micropillar

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Eye and Vision 2019年第1期6卷 322-330页

作者： Ke Cao Srujana Sahebjada Andrea j.Richardson paul N.Baird Centre for Eye Research Australia Royal Victorian Eye and Ear HospitalMelbourneAustralia. Department of Surgery OphthalmologyThe University of Melbourne32 Gisborne StreetEast MelbourneVIC 3000Australia

Background:Keratoconus(KC)is a common corneal condition with an unknown gender *** numerous studies have investigated the genetic component of KC,no specific genes have yet been attributed to the *** recently reported posterior segment changes occurring in the eyes of KC ***,it is not clear whether these changes are part of KC pathogenesis or reflect changes in anatomical features of the eye manifested by changes at the *** retinal changes represent the main characteristics observed in agerelated macular degeneration(AMD)and that pleiotropy has been demonstrated between different eye diseases,we wished to assess if known AMD associated genes were also associated with ***:A total of 248 KC subjects and 366 non-KC(control)subjects were recruited from public and private clinics in Melbourne for this *** single nucleotide polymorphisms(SNPs)previously associated with AMD,including rs10490924(ARMS2/HTRA1),rs10737680(CFH),rs13278062(TNFRSF10A),rs1864163(CETP),rs2230199(C3),rs3130783(IER3/DDR1),rs334353(TGFBR1),rs3812111(COL10A1),rs429608(C2/CFB),rs4420638(APOE),rs4698775(CFI),rs5749482(TIMP3),rs6795735(ADAMTS9),rs8017304(RAD51B),rs8135665(SLC16A8),rs920915(LIPC),rs943080(VEGFA),rs9542236(B3GALTL)and rs13081855(COL8A1/FILIP1L),were genotyped in this *** regression was applied to evaluate the association between these SNPs and KC on both genders together,as well as each gender *** regression was also applied to assess the association between SNPs and corneal *** correction was applied to adjust for multiple ***:Genotyping data were available for 18 *** SNP,rs6795735(ADAMTS9)was significantly associated with KC(p=3.5×10−4)when both genders were assessed,whereas rs5749482(TIMP3)was only associated in males(p=7.7×10−4)following Bonferroni multiple ***,when the covariates of age and gender were included,the associations became non-sign

关键词： Keratoconus Gender Genetic Age-related macular degeneration

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Comprehensive validation of a diagnostic strategy for sequencing genes with one or multiple pseudogenes using pseudoxanthoma elasticum as a model

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journal of Genetics and Genomics 2021年第4期48卷 289-299页

作者： Wouter Steyaert Shana Verschuere paul j.Coucke Olivier M.Vanakker Center for Medical Genetics Ghent University HospitalGhentBelgium bDepartment of Biomolecular Medicine Ghent UniversityGhentBelgium Department of Human Genetics Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenthe Netherlands

Pseudogenes are frequently encountered noncoding sequences with a high sequence similarity to their protein-coding *** this reason,their presence is often considered troublesome in molecular *** pseudoxanthoma elasticum(PXE),a disease predominantly caused by mutations in ATPbinding cassette family C member 6(ABCC6),the presence of two pseudogenes complicates the analysis of sequence *** whole-exome sequencing(WES)becoming the standard of care in molecular diagnostics,we wanted to evaluate whether this technique is as reliable as gene-specific targeted enrichment analysis for the analysis of *** established a PCR-based targeted enrichment and next-generation sequencing testing approach and demonstrated that the ABCC6-specific enrichment combined with the applied mapping algorithm overcomes the complication of ABCC6 pseudogene aspecificities,contrary to *** propose a time-and cost-efficient diagnostic strategy for comprehensive and accurate molecular genetic testing of PXE,which is highly automatable.

关键词： Pseudoxanthoma elasticum ABCC6 Pseudogenes Next-generation sequencing Whole-exome sequencing Targeted enrichment

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