The Inveterate Tinkerer 11. Marangoni Effect

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The eleventh article in this series demonstrates the Marangoni effect.     

The Inveterate Tinkerer

In this series of articles, the author discusses various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The twelfth article in this series demonstrates some experiments with air bubbles in liquids.     

The Inveterate Tinkerer

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The thirteenth article in this series demonstrates some experiments with Hele–Shaw cells.     

The inveterate tinkerer 1. Salt oscillator

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The first article in this series is about the salt oscillator — a hydrodynamic curiosity.     

The inveterate tinkerer

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The eighth article in this series explores and demonstrates Kelvin–Helmholtz instability     

The inveterate tinkerer 9. Rayleigh–Taylor instability

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The ninth article in this series explores and demonstrates Rayleigh–Taylor instability.     

The inveterate tinkerer

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The seventh article in this series explores the formation, structure, and properties of antibubbles.     

The inveterate tinkerer 3. Experiments with vortex rings

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The third article in this series is about vortex rings and some interesting experiments based on them.     

The inveterate tinkerer 10. Analog computing with soap films

In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via table-top experiments using low-cost or home-made instruments. The tenth article in this series demonstrates the use of the area-minimization property of soap films in the computation of analog solutions to mathematical problems.     

The inveterate tinkerer: Bubble raft

In this section of Resonance, we invite readers to pose questions likely to be raised in a classroom situation. We may suggest strategies for dealing with them, or invite responses, or both. “Classroom” is equally a forum for raising broader issues and sharing personal experiences and viewpoints on matters related to teaching and learning science.In this series of articles, the authors discuss various phenomena in fluid dynamics, which may be investigated via tabletop experiments using low-cost or home-made instruments. The sixth article in this series explores crystalline defects and motion of dislocations using bubble rafts. Materials     

The Inveterate Tinkerer 16. Flow Visualisation

We conclude our series of articles on experiments in fluid dynamics by listing the materials and methods employed, as well as discuss a few experimental techniques which were not considered in earlier articles. Several books on flow visualisation [1, 2] are available which the reader may wish to refer.     

Some factors underlying mathematical performance: The role of visuospatial working memory and non-verbal intelligence

Passive and active visuospatial working memory (VSWM) were investigated in relation to maths performance. The mental rotation task was employed as a measure of active VSWM whereas passive VSWM was investigated using a modified Corsi Blocks task and a matrix pattern task. The Raven Progressive Matrices Test measured fluid intelligence. A total of 128 students, aged 15–16, served as participants. Fluid intelligence and passive VSWM accounted for variance in overall maths performance. Active VSWM exhibited significant correlations with maths measures, but in a series of regression analyses most of its effect was observed to be mediated by fluid intelligence. Different subscores of mathematical skills (geometry, word problems, and mental arithmetic) were accounted for by fluid intelligence and different measures of VSWM. The educational implications of the results are discussed.     

磁流体的制备与分散技术

本文利用酸蚀法和复合法分别制备了复合铁酸锌镍、铁酸锌、铁酸镍、铁酸钡磁流体,通过沉降实验,重点考察了这些磁性纳米粉在水相中的分散方法和技术,对磁性粉体的液相分散技术进行了探讨。     

Shifting positionalities across international locations: Embodied knowledge,time‐geography,and the polyvalence of privilege

Despite a robust body of scholarship on positionality, the practice of international Higher Education research often neglects engagement with the varied, fluid and complex positionalities of researchers across national boundaries. Through a series of vignettes, the authors argue for reflexivity that extends beyond rigid social identities and towards embodied knowledge, or self‐understanding that is mutable and context responsive. For international mobile researchers especially, new affinities can evolve through propinquity and social custom, and gradually become incorporated into self‐knowledge with the passing of time. Beyond mere cultural competency, this article raises the importance of symbolic competency that simultaneously negotiates the multiple dimensions of language, various forms of capital, as well as evolving social identities in conducting research in different contexts.     

Analysis on the Translation Strategies in English humor

<正>1.Definition and connotation of humor The English word"humor"came from Latin originally which was used to refer to"wet"and"fluid"After a series of evolution,it finally evolved into the word used in daily life in the16th century.Then it was used to describe a kind of people who are humorous,funny and clever.Humor is a cultural phenomenon based on language.There are     

衡阳市水安全评价及水资源可持续利用对策

水资源是人类生命的源泉,进入21世纪,人们越来越重视水安全的研究。衡阳市地属湘江流域,水资源总量比较丰富,但由于自然和人为的种种原因,水安全问题突出。本文从水资源总量、水质、工程等方面对衡阳市进行水安全定性评价,探讨水安全问题的根源,有针对性地提出加强水利设施建设、节水、普及水资源利用的安全意识、加强水资源管理一体化等一系列水资源可持续利用对策。     

Exact solutions for steady flows of second-grade fluids

This paper aims to investigate exact solutions for a second-grade fluid flow with the inverse method. By assuming the relation between the vorticity field and the streamfunction, the exact solutions of the motion of plane second-grade fluids are investigated and obtained. The solutions obtained include simple Couette flows, slit jet flows and uniform flows over a series of distributed obstacles. Project supported by the National Natural Science Foundation of China (Grant No.10472063)     

轻质球形水处理滤料的研制

以粘土为主要原料，加入适量的化工原料，生产出较理想的水处理滤料－一种轻质陶粒。该滤料有强度大、空隙率大、比表面积大、化学稳定性好、生物附着力强、挂膜性能良好、水流流态好、反冲容易进行的特点。通过曝气生物滤池处理城市污水的试验表明，这种滤料具有很好的处理效果。     

Modeling complexity and difficulty in measures of fluid intelligence

This article applies structural equation modeling to the simultaneous study of task complexity and difficulty in measures of fluid intelligence. The interrelation between 3 tests of fluid intelligence, 2 experimental tasks, and age is examined. Each experimental task is decomposed into 4 subtasks, with the most intellectually demanding ones being measures of fluid intelligence, and the remaining 3 levels constructed to be gradually simpler. The findings suggest that the experimental manipulations produced systematic changes in 3 sets of parameters. These are: (a) the mean intercept parameters of the structural equation model—interpreted as “pure test difficulties” reflecting task‐specific demands placed on elementary cognitive processes of the “same kind” (b) factor loadings on 2 subtask‐specific narrow factors (SWAPS and TRIPLETS) that reflect demands placed on processes of “similar kinds,” that is, processes common to variations within the same experimental task; and (c) factor loadings on a fluid intelligence factor (Gf) that reflect demands placed on processes of “diverse kinds,” which are common to measures of a broad range of different cognitive tasks. The results indicate that as task requirements become more demanding, cognitive processes of the same kind, which are involved in solving the easier subtasks, are no longer critical to performance, but the demand on processes of similar and diverse kinds is increased. It is suggested that for human subjects, increase in task complexity may be associated with lapses of attention in the course of carrying out a series of interconnected steps.     

Eccentricity and thermoviscous effects on ultrasonic scattering from a liquid-coated fluid cylinder

Calculation of the scattered field of the eccentric scatterers is an old problem with numerous applications. This study considers the interaction of a plane compressional sound wave with a liquid-encapsulated thermoviscous fluid cylinder submerged in an unbounded viscous thermally conducting medium. The translational addition theorem for cylindrical wave functions, the appropriate wave field expansions and the pertinent boundary conditions are employed to develop a closed-form solution in the form of infinite series. The analytical results are illustrated with a numerical example in which the compound cylinder is insonified by a plane sound wave at selected angles of incidence in a wide range of dimensionless frequencies. The backscattered far-field acoustic pressure amplitude and the spatial distribution of the total acoustic pressure in the vicinity of the cylinder are evaluated and discussed for representative values of the parameters characterizing the system. The effects of incident wave frequency, angle of incidence, fluid thermoviscosity, core eccentricity and size are thoroughly examined. Limiting case involving an ideal compressible liquid-coated cylinder is considered and fair agreement with a well-known solution is established.