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In situ characterization of particle formation in spray flame synthesis using wide-angle light scattering

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Particuology 2024年第3期86卷 304-312页

作者： simon Aβmann Franz j.T.Huber Stefan Will Lehrstuhl für Technische Thermodynamik(LTT) Friedrich-Alexander-Universitat Erlangen-Nürnberg(FAU)Erlangen91058Germany Erlangen Graduate Schoolin Advanced Optical Technologies(SAOT) Friedrich-Alexander-Universitat Erlangen-Nurnberg(FAU)Erlangen91052Germany Competence Unit Engineering of Advanced Materials(EAM) Friedrich-Alexander-Universitat Erlangen-Nürnberg(FAU)Erlangen91052Germany

Wide-angle light scattering(WALS)was used for in situ measurements of droplet and nanoparticle size distributions during the synthesis of titania and iron oxide particles from liquid precursor solutions in the standardized SpraySyn burner for spray flame *** was synthesized from titanium tetraisopropoxide(TTIP)and iron oxide from iron(II)nitrate nonahydrate(INN)using ethanol(EtOH)as *** images were taken at heights up to 120 mm above the burner surface and classified into droplet and particle *** size distributions were derived from a sequential analysis of scattering data containing the oscillating Mie pattern,the lognormal size distribution parameters for spherical and fractal particle fractions from a multivariate approach on averaged particle scattering *** results show that the precursor addition leads to altered evaporation behavior and even droplet disruption probably induced by puffing or micro-explosions compared to pure *** the case of TTIP(a hygroscopic alkoxide),the synthesis of a large fraction of spheres was observed,while the nitrate INN leads to the formation of mostly fractal aggregates.

关键词： Spray flame synthesis Metal oxide particles Elastic light scattering Droplet size distribution Nanoparticle morphology Particle size distribution

Ileal pouch surgery for ulcerative colitis

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World journal of Gastroenterology 2007年第24期13卷 3288-3300页

作者： simon P Bach Neil j Mortensen Department of Colorectal Surgery John Radcliffe Hospital Oxford OX3 9DU United Kingdom

Ulcerative colitis (UC) is a relapsing and remitting disease characterised by chronic mucosal and submucosal inflammation of the colon and rectum. Treatment may vary depending upon the extent and severity of inflammation. Broadly speaking medical treatments aim to induce and then maintain remission. Surgery is indicated for inflammatory disease that is refractory to medical treatment or in cases of neoplastic transformation. Approximately 25% of patients with UC ultimately require colectomy. Ileal pouch-anal anastomosis (IPAA) has become the standard of care for patients with ulcerative colitis who ultimately require colectomy. This review will examine indications for IPAA, patient selection, technical aspects of surgery, management of complications and long term outcome following this procedure.

关键词： Ulcerative colitis Ileal Pouch Ileal pouch anal anastomosis

Analysis of Longitudinal Profiles along the Eastern Margin of the Qinghai-Tibetan Plateau

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journal of Mountain Science 2013年第4期10卷 643-657页

作者： simon j. Aiken Gary j. Brierley School of Environment the University of AucklandAuckland 1010 New Zealand

Resulting from the collision of the Eurasian and Indian plates, the Qinghai-Tibetan Plateau is commonly known as the ＇roof of the world＇. Collectively the Yarlung Tsangpo, Nu, Laneang, Yangtze, Yalong, and Yellow River basins drain the eastern margin of the plateau. In this paper, we utilize Shuttle Radar Topography Mission elevation data to examine morphometric and relief attributes of these basins to reveal insights rates of incision. A robust into tectonic activity and technique using Maflab is proposed to alleviate errors associated with SRTM data in the derivation of river longitudinal profiles. Convex longitudinal profiles are interpreted to be a product of uplift rates that exceed rates of channel incision along the entire margin of the Qinghai- Tibetan Plateau. Highest relief towards the south reflects extensive fluvial incision. High relief is also prominent along major active faults. Erosion patterns are related to distance from knickpoints. Highest rates of erosion and incision are evident towards the south, with decreasing values towards the north, suggesting a link between tectonic activity and erosion.

关键词： Longitudinal profile Erosion Relief Tectonics Qinghai-Tibetan Plateau

Influence of interparticle interactions on the kinetics of self-assembly and mechanical strength of nanoparticulate aggregates

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Particuology 2009年第2期7卷 106-113页

作者： Roberto Moreno-Atanasio simon j.Antony Richard A.Williams Institute of Particle Science and Engineering University of LeedsLeedsLS2 9JTUnited Kingdom

Computer simulations based on Discrete Element Method have been performed in order to investigate the influence of interparticle interactions on the kinetics of self-assembly and the mechanical strength of nanoparticle aggregates. Three different systems have been considered. In the first system the interaction between particles has been simulated using the jKR （johnson, Kendall and Roberts） contact theory, while in the second and third systems the interaction between particles has been simulated using van der Waals and electrostatic forces respectively. In order to compare the mechanical behaviour of the three systems, the magnitude of the maximum attractive force between particles has been kept the same in all cases. However, the relationship between force and separation distance differs from case to case and thus, the range of the interparticle force. The results clearly indicate that as the range of the interparticle force increases, the self-assembly process is faster and the work required to produce the mechanical failure of the assemblies increases by more than one order of magnitude.

关键词： Nanoparticles Discrete Element Method (DEM) Self-assembly jKR model van der Waals force

Design of face-hobbed spiral bevel gears with reduced maximum tooth contact pressure and transmission errors

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Chinese journal of Aeronautics 2013年第3期26卷 777-790页

作者： Vilmos simon Budapest University of Technology and Economics Faculty of Mechanical Engineering Department for Machine Design

The aim of this study is to define optimal tooth modifications, introduced by appropriately chosen head-cutter geometry and machine tool setting, to simultaneously minimize tooth contact pressure and angular displacement error of the driven gear （transmission error） of face-hobbed spiral bevel gears. As a result of these modifications, the gear pair becomes mismatched, and a point contact replaces the theoretical line contact. In the applied loaded tooth contact analysis it is assumed that the point contact under load is spreading over a surface along the whole or part of the ‘‘potential’’ contact line. A computer program was developed to implement the formulation provided above. By using this program the influence of tooth modifications introduced by the variation in machine tool settings and in head cutter data on load and pressure distributions, transmission errors, and fillet stresses is investigated and discussed. The correlation between the ease-off obtained by pinion tooth modifications and the corresponding tooth contact pressure distribution is investigated and the obtained results are presented.

关键词： Ease-off Face-hobbed spiral bevel gears Load distribution Transmission errors Gear teeth

Identification of Differentially Senescing Mutants of Wheat and Impacts on Yield,Biomass and Nitrogen Partitioning

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journal of Integrative Plant Biology 2012年第8期54卷 555-566页

作者： Adinda P.Derkx simon Orford simon Griffiths M.john Foulkes Malcolm j. Hawkesford Plant Biology and Crop Science Department Rothamsted ResearchHarpendenHertfordshireAL5 2JQUK Division of Plant&Crop Sciences School of BiosciencesUniversity of NottinghamSutton Bonington CampusNr LoughboroughLE12 5RDUK john Innes Centre Norwich Research ParkColneyNorwich NR4 7UHUK

Increasing photosynthetic capacity by extending canopy longevity during grain filling using slow senescing stay-green genotypes is a possible means to improve yield in wheat. Ethyl methanesulfonate （EMS） mutated wheat lines （Triticum aestivum L. cv. Paragon） were screened for fast and slow canopy senescence to investigate the impact on yield and nitrogen partitioning. Stay-green and fast-senescing lines with similar anthesis dates were characterised in detail. Delayed senescence was only apparent at higher nitrogen supply with low nitrogen supply enhancing the rate of senescence in all lines. In the stay-green line 3 （SG3）, on a whole plant basis, tiller and seed number increased whilst thousand grain weight （TGW） decreased; although a greater N uptake was observed in the main tiller, yield was not affected. In fast-senescing line 2 （FS2）, yield decreased, principally as a result of decreased TGW. Analysis of N-partitioning in the main stem indicated that although the slow-senescing line had lower biomass and consequently less nitrogen in all plant parts, the proportion of biomass and nitrogen in the flag leaf was greater at anthesis compared to the other lines; this contributed to the grain N and yield of the slow-senescing line at maturity in both the main tiller and in the whole plant. A field trial confirmed senescence patterns of the two lines, and the negative impact on yield for FS2 and a positive impact for SG3 at low N only. The lack of increased yield in the slow-senescing line was likely due to decreased biomass and additionally a possible sink limitation.

关键词： Wheat senescence stay-green grain-filling yield nitrogen.

Method of cells-based multiscale modeling of elastic properties of filament wound C/C-SiC including free Si and matrix porosity

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journal of Materials Science & Technology 2019年第12期35卷 2906-2918页

作者： Evan j.Pineda Marek Fassin Stefanie Reese jaan-Willem simon NASA Glenn Research Center 21000 Brookpark RoadMS 49/7ClevelandOH 44135United States Institute for Applied Mechanics RWTH Aachen UniversityMies-van-der-Rohe-Str.152074 AachenGermany

Three different multiscale models, based on the method of cells(generalized and high fidelity) micromechanics models were developed and used to predict the elastic properties of C/C-SiC composites. In particular, the following multiscale modeling strategies were employed: Concurrent modeling of all phases using the generalized method of cells, synergistic(two-way coupling in space) multiscale modeling with the generalized method of cells, and hierarchical(one-way coupling in space) multiscale modeling with the high fidelity generalized method of cells. The three models are validated against data from a hierarchical multiscale finite element model in the literature for a repeating unit cell of C/***, the multiscale models are used in conjunction with classical lamination theory to predict the stiffness of C/C-SiC plates manufactured via a wet filament winding and liquid silicon infiltration process recently developed by the German Aerospace Institute. Finally, un-reacted Si(or free Si) and porosity in the C matrix are included in the multiscale model, and the effect of these new phases on the stiffness and local stresses are considered.

关键词： Multiscale modeling C/C-SiC Ceramic matrix composites

Analysis of the human Atox 1 homologue in Wilson patients

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World journal of Gastroenterology 2008年第15期14卷 2383-2387页

作者： Isabel simon Mark Schaefer jürgen Reichert Wolfgang Stremmel Department of Gastroenterology University of HeidelbergGermany

AIM: To analyze the metallochaperone antioxidant-1 (Atox1) gene sequence in Wilson disease patients. METHODS: Mutation analysis of the four exons of the Atox1 gene including the intron- exon boundaries was performed in 63 Wilson disease patients by direct sequencing. RESULTS: From 63 selected patients no mutations were identified after the entire coding region including the intron- exon boundaries of Atox1 were sequenced. One known polymorphism within the Atox1 gene (5’UTR -99 T>C) in 31 (49%) of the Wilson patients as well as one previously undescribed variation (5’UTR -68 C>T) in 2 of the Wilson patients could be detected. Statistical analyses revealed that the existence of a variation within the Atox1- gene showed a tendency towards an earlier onset of the disease. CONCLUSION: Based on the data of this study, no major role can be attributed to Atox1 in the pathophysiology or clinical variation of Wilson disease.

关键词： Antioxidant-1 Wilson disease Wilson's disease protein Mutation analysis

Learning from the heaviest ancient whale

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The Innovation 2023年第5期4卷 21-22页

作者： Peijun Zhang simon j.Goodman Marine Mammal and Marine Bioacoustics Laboratory Institute of Deep-sea Science and EngineeringChinese Academy of Sciences28 Luhuitou RoadSanya 572000China School of Biology Faculty of Biological SciencesUniversity of LeedsLeeds LS29JTUK

A groundbreaking study published in Nature by Bianucci et *** reported the discovery of a new basilosaurid species,Perucetus colossus(Figure 1).The incomplete fossil skeleton found in Peru is around 39 million years *** ancient whale challenges the long-held belief that the blue whale represents the largest known animal to have ever lived on *** is estimated to have had a body mass between 85 and 340 tons,with an average of 180 tons.1 In comparison,extant blue whales have an estimated body mass of 100–150 *** new study proposes that *** was adapted to a fully aquatic lifestyle in shallow water with slow swimming speeds,similar to extant *** bone mass would have aided buoyancy control while diving to shallow depths,as seen in modern-day *** new discovery not only challenges our understanding of mammalian maximum body mass evolution,but it also expands our knowledge of the lifestyle of ancient cetaceans.

关键词： shallow Figure ancient