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On Pattern Selection in Three-Dimensional Benard-Marangoni Flows

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Communications in Computational Physics 2012年第3期11卷 893-924页

作者： Arne Morten Kvarving tormod bjøntegaard Einar M.Rønquist Department of Mathematical Sciences Norwegian University of Science and Technology(NTNU)Norway

In this paper we study B´enard-Marangoni convection in confined containers where a thin fluid layer is heated from *** consider containers with circular,square and hexagonal *** Marangoni numbers close to the critical Marangoni number,the flow patterns are dominated by the appearance of the wellknown hexagonal convection *** main purpose of this computational study is to explore the possible patterns the systemmay end up in for a given set of *** a series of numerical experiments,the coupled fluid-thermal system is started with a zero initial condition for the velocity and a random initial condition for the *** a given set of parameters we demonstrate that the system can end up in more than one *** example,the final state of the system may be dominated by a steady convection pattern with a fixed number of cells,however,the same system may occasionally end up in a steady pattern involving a slightly different number of cells,or it may end up in a state where most of the cells are stationary,while one or more cells end up in an oscillatory *** larger aspect ratio containers,we are also able to reproduce dislocations in the convection pattern,which have also been observed *** has been conjectured that such imperfections(e.g.,a localized star-like pattern)are due to small irregularities in the experimental setup(e.g.,the geometry of the container).However,we show,through controlled numerical experiments,that such phenomena may appear under otherwise ideal *** repeating the numerical experiments for the same non-dimensional numbers,using a different random initial condition for the temperature in each case,we are able to get an indication of how rare such events ***,we study the effect of symmetrizing the initial ***,we study the effect of selected geometry deformations on the resulting convection patterns.

关键词： B´enard-Marangoni spectral elements pattern formation

Violent collisions can reveal hexadecapole deformation of nuclei

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Nuclear Science and Techniques 2024年第7期35卷 1-3页

作者： björn Schenke Physics Department Brookhaven National LaboratoryUptonNY 11973USA

A new observable in heavy ion collision experiments was identified to be sensitive to the hexadecapole deformation of the colliding *** deformation is difficult to measure in traditional nuclear electric transition measurements,as it is often overwhelmed by the nuclear quadrupole *** opens the door to gain new insight into nuclear structure with experiments that were designed to study hot and dense nuclear matter.

关键词： deformation collision insight

Norwegian oil and gas storage in rock caverns-Technology based on experience from hydropower development

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 479-486页

作者： bjørn Nilsen Department of Geoscience and Petroleum Norwegian University of Science and Technology(NTNU)TrondheimNorway

Underground storage in rock caverns is widely used in Norway for many different petroleum products,such as crude oil,fuel,propane and ***,the caverns for such storages are unlined,*** is ensured without using any steel lining or *** main basis for the storage technology originates from the extensive hydropower development in *** part of this activity,about 4500 km of tunnels and shafts have been excavated,and around 200 large powerhouse caverns have been *** hydropower tunnels are mainly unlined,with hydrostatic water pressure on unlined rock of up to 1000 *** of the projects also include air cushion chambers with volumes of up to 1×10^(5)m^(3)and air pressure up to 7.7 *** lessons which are valuable also for underground oil and gas storage have been learnt from these *** a storage project to become successful,systematic,well planned design and ground investigation procedures are *** main steps of the design procedure are first to define the optimum location of the project,and then to optimize orientation,shape/geometry and dimensions of caverns and *** part of the procedure,ground investigations have to be carried out at several steps integrated with the progress of *** investigation and design procedures,and the great significance of these for the project to become successful will be *** examples of oil and gas storage in unlined rock caverns are given,illustrating the relevancy of experience from high-pressure hydropower projects for planning and design of unlined caverns for oil and gas storage.

关键词： Underground storage Oil Gas Liquefied petroleum gas(LPG) Hydropower Air cushion chamber

What is required for better progress in clinical and scientific andrology involving sperm assessments?

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Asian Journal of Andrology 2024年第3期26卷 229-232页

作者： Lars björndahl ANOVA Karolinska University Hospital and Karolinska Institutet Sweden Stockholm S-113 64

In scientific publications based on basicsemen examination,there is a generallack of consistency and transparencyregarding laboratory techniques *** support improvements in clinicaland scientific andrology,it is essential toincrease understanding of basic physiologyand biology,and enhance compliancewith existing recommendations andinternational *** designsneed to be improved as well as transparencyof laboratory methods used and openpublication of data obtained.

关键词： transparency consistency clinical

Takotsubo triggered by acute myocardial infarction：a common but overlooked syndrome？

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Journal of Geriatric Cardiology 2014年第2期11卷 171-173页

作者： bj orn Redfors Wallenberg Laboratory Department of Molecular and Clinical Medicine Sahlgrenska Academy at University of Gothenburg Bruna Straket 16 413 45 Go-thenburg Sweden Department of Cardiology Sahlgrenska University Hospital Bruna Straket 16 413 45 Gothenburg Sweden

Takotsubo cardiomyopathy （TCM） is an acute cardiac syndrome characterized by extensive, but potentially reversible, left ventricular dysfunction in the absence of an explanatory coronary obstruction. Thus, TCM is distinct from coronary artery disease （CAD） and acute myocardial infarction （AMI）. However, substantial evidence for co-existing CAD in some TCM patients exist. Herein, we take this associa-tion one step further and present a case in which the patient simultaneously suffered from AMI and TCM, and in which we believe that a primary coronary event triggered TCM. An 88-year-old female presented with chest pain. Echocardiography revealed apical akinesia with hypercontractile bases. An occluded diagonal branch with suspected acute plaque rupture was identified on the angiogram, but could not explain the extent of akinesia. Cardiac function recovered completely. Thus, this patient adhered to current diagnostic criteria for TCM. TCM is a well-known complication for other conditions associated with somatic stress. It is therefore intuitive to assume that AMI, which also associates with somatic stress and elevated catecholamine, can cause TCM. Our case illustrates that TCM and AMI may occur simulta-neously. Although causality cannot be conclusively inferred from this association, the somatic stress associated with AMI may have caused TCM in this patient.

关键词： Acute myocardial infaction Catecholamine Coronary artery disease Somatic stress Takotsubo cardiomyopathy

Influence of amphiphilic structures on the stability of polyphenols with different hydrophobicity

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Science China Chemistry 2007年第1期50卷 121-126页

作者： Bergensthl bjRN Food Technology Center for Chemistry and Chemical EngineeringLund UniversityPO Box 124S-22100LundSweden

Autooxidation of five polyphenols representing range of different hydrophobicities(catechin gallate (CG),(-)catechin((-)C),epicatechin(EC),epigallocatechin gallate(EGCG)and epigallocatechin(EGC)) in three different aqueous solutions:molecular solution,micellar solution(Tween-20)and liposomal dispersion(soybean lecithin)was monitored by *** rate of oxidation of the five polyphenols was higher at pH 4.5 than at pH *** with the control,addition of Tween-20(micellar structure)and lecithin(liposomal structure)significantly decreased the degradation of *** the presence of lecithin the autooxidation of all the five polyphenols was slower than in the presence of Tween-20. The effective protection of the colloidal structures was compared with the hydrophobicity of the poly- phenols estimated from the partitioning between octanol and *** protection from oxidation in the presence of the colloidal structures(micellar or liposomal)increased with increasing partitioning of a polyphenol towards the hydrophobic *** protecting effect of the colloidal structures was more effective at pH 4.5 than at pH 3.5.

关键词： amphiphilic structures autooxidation polyphenols K value effective protection

Solanaceae pangenomes are coming of graphical age to bring heritability back

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aBIOTECH 2022年第4期3卷 233-236页

作者： björn Usadel Institute for Biological Data Science CEPLASHeinrich Heine UniversityDüsseldorfGermany IBG-4 Bioinformatics BioSCForschungszentrum JülichJülichGermany

Two recent articles describe a pangenome of potato and a graph-based pangenome for tomato,*** latter improves our understanding of the tomato genomics architecture even further and the use of this graph-based pangenom... 详细信息

关键词： Tomato Potato Pangenome Graph-based pangenome Heritability

Diagnosis and treatment of pancreatic exocrine insufficiency

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World Journal of Gastroenterology 2013年第42期19卷 7258-7266页

作者： bjrn Lindkvist Institute of Medicine Sahlgrenska AcademyUniversity of GothenburgSE-413 45 GothenburgSweden Division of Gastroenterology and Hepatology Department of Internal MedicineSahlgrenska University HospitalSE-413 45 GothenburgSweden

Pancreatic exocrine insufficiency is an important cause of maldigestion and a major complication in chronic *** digestion requires adequate stimulation of pancreatic secretion,sufficient production of digestive enzymes by pancreatic acinar cells,a pancreatic duct system without significant outflow obstruction and adequate mixing of the pancreatic juice with ingested *** in any of these steps may result in pancreatic exocrine insufficiency,which leads to steatorrhea,weight loss and malnutrition-related complications,such as *** evaluating digestion,such as fecal fat quantification and the13C-mixed triglycerides test,are the most accurate tests for pancreatic exocrine insufficiency,but the probability of the diagnosis can also be estimated based on symptoms,signs of malnutrition in blood tests,fecal elastase 1 levels and signs of morphologically severe chronic pancreatitis on *** for pancreatic exocrine insufficiency includes support to stop smoking and alcohol consumption,dietary consultation,enzyme replacement therapy and a structured follow-up of nutritional status and the effect of *** enzyme replacement therapy is administered in the form of enteric-coated minimicro-spheres during *** dose should be in proportion to the fat content of the meal,usually 40-50000 lipase units per main meal,and half the dose is required for a *** cases that do not respond to initial treatment,the doses can be doubled,and proton inhibitors can be added to the *** review focuses on current concepts of the diagnosis and treatment of pancreatic exocrine insufficiency.

关键词： Chronic pancreatitis Pancreatic exocrine insufficiency Pancreatic enzyme replacement therapy

Is a catalyst always beneficial in plasma catalysis? Insights from the many physical and chemical interactions

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Journal of Energy Chemistry 2023年第10期85卷 501-533,I0013页

作者： björn Loenders Roel Michiels Annemie Bogaerts Research group PLASMANT Department of ChemistryUniversity of AntwerpUniversiteitsplein 1B-2610 Wilrijk-AntwerpBelgium

Plasma-catalytic dry reforming of CH_(4)(DRM) is promising to convert the greenhouse gasses CH_(4) and CO_(2) into value-added chemicals, thus simultaneously providing an alternative to fossil resources as feedstock for the chemical industry. However, while many experiments have been dedicated to plasma-catalytic DRM, there is no consensus yet in literature on the optimal choice of catalyst for targeted products,because the underlying mechanisms are far from understood. Indeed, plasma catalysis is very complex,as it encompasses various chemical and physical interactions between plasma and catalyst, which depend on many parameters. This complexity hampers the comparison of experimental results from different studies, which, in our opinion, is an important bottleneck in the further development of this promising research field. Hence, in this perspective paper, we describe the important physical and chemical effects that should be accounted for when designing plasma-catalytic experiments in general, high-lighting the need for standardized experimental setups, as well as careful documentation of packing properties and reaction conditions, to further advance this research field. On the other hand, many parameters also create many windows of opportunity for further optimizing plasma-catalytic ***, various experiments also reveal the lack of improvement in plasma catalysis compared to plasma-only, specifically for DRM, but the underlying mechanisms are unclear. Therefore, we present our newly developed coupled plasma-surface kinetics model for DRM, to provide more insight in the underlying reasons. Our model illustrates that transition metal catalysts can adversely affect plasmacatalytic DRM, if radicals dominate the plasma-catalyst interactions. Thus, we demonstrate that a good understanding of the plasma-catalyst interactions is crucial to avoiding conditions at which these interactions negatively affect the results, and we provide some recommendations for im

关键词： Plasma catalysis Dry reforming of methane Discharges Reaction kinetics Modelling