Ureteroscopy is a minimally invasive surgical procedure for the removal of kidney stones. A ureteroscope, containing a hollow, cylindrical working channel, is inserted into the patient's kidney. The renal space proximal to the scope tip is irrigated, to clear stone particles and debris, with a saline solution that flows in through the working channel. We consider the fluid dynamics of irrigation fluid within the renal pelvis, resulting from the emerging jet through the working channel and return flow through an access sheath. Representing the renal pelvis as a two-dimensional rectangular cavity, we investigate the effects of flow rate and cavity size on flow structure and subsequent clearance time of debris. Fluid flow is modelled with the steady incompressible Navier–Stokes equations, with an imposed Poiseuille profile at the inlet boundary to model the jet of saline, and zero-stress conditions on the outlets. The resulting flow patterns in the cavity contain multiple vortical structures. We demonstrate the existence of multiple solutions dependent on the Reynolds number of the flow and the aspect ratio of the cavity using complementary numerical simulations and particle image velocimetry experiments. The clearance of an initial debris cloud is simulated via solutions to an advection–diffusion equation and we characterise the effects of the initial position of the debris cloud within the vortical flow and the Péclet number on clearance time. With only weak diffusion, debris that initiates within closed streamlines can become trapped. We discuss a flow manipulation strategy to extract debris from vortices and decrease washout time.

This paper considers the significant role of cross-sectional geometry on resistance in co-axial pipe flows. We consider an axially flowing viscous fluid in between two long and thin elliptical coaxial cylinders, one inside the other. The outer cylinder is stationary, while the inner cylinder (rod) is free to move. The rod poses a resistance to the axial flow, while the viscous fluid poses a resistance to any motion of the rod. We show that the equations for flow in the axial direction – driven by a prescribed flux – and for flow within the cross-section of the domain – driven by the motion of the rod – decouple in the asymptotic limit of small cylinder aspect ratio into axial Poiseuille flow and transverse Stokes flow, respectively. The objective of this paper is to calculate numerically the axial and cross-sectional resistances and to determine their dependence on cross-sectional geometry – i.e. rod position and the ellipticities of the rod and bounding cylinder. We characterise axial resistance, first for three reduced parameter spaces that have not been fully analysed in the literature: (i) a circle in an ellipse, (ii) an ellipse in a circle and (iii) an ellipse in an ellipse of equal eccentricity and orientation, before extending our geometric parameter space to determine the overall optimal geometry to minimise axial flow resistance for fixed cross-sectional area. Cross-sectional resistance is characterised via coefficients in a Stokes resistance matrix and we highlight the interdependent effects of cross-sectional ellipticity and boundary interactions.

The publication of Batts 1971 (the actual scribal spellings in MSS A, B, C of the Nibelungenlied) and of Bäuml-Fallone 1976 (A concordance to the Nibelungenlied) for the first time have provided access to scribal spellings as the most direct evidence for the phonological structure of Middle High German (at least in this important work). This study is limited to the velar stops, affricates, fricatives. The scribal spellings together with historical eveidence and the modern dialects suggest the full structure of the velars. Finally, it is shown that the “normalized spelling” is in three respects misleading, at least for the Nibelungenlied.

When our Secretary, George Winchester Stone, asked me last July to address this meeting on the general topic of language teaching and linguistics, it was only with considerable hesitation that I finally agreed to accept. There has been far too much loose talk recently about the application of linguistics to language teaching, and I did not wish to add to it. In some circles linguistics has turned into a sort of fad. There are those who talk of the “linguistic method” of language teaching, as if to oppose it to some hypothetical “non-linguistic method” used in the benighted past. And at meetings of language teachers, bright young things walk up to me and ask, apparently in all seriousness: “Excuse me, professor, but would you please tell me how linguistics handles the subjunctive?” Needless to say, I have no answers to such questions; they merely embarrass me. Linguistics is not a teaching method, but a growing body of knowledge and theory; and though it may offer helpful answers to some of the problems of language teaching, it surely does not know all the answers.

During recent years language teachers have heard a great many claims about the importance of linguistics in language teaching. It is true that, during the last thirty years or so, many useful and rather exact techniques have been developed for the analysis and description of languages, and along with them have come many new attitudes toward language in general. Some of this must obviously have a bearing on language teaching. Yet when the hard pressed language teacher tries to learn something about this new science of linguistics, he finds it exasperatingly hard to do so. If he asks a linguistics colleague for an opinion on the recent popular books on language (some of which have been real best sellers), he is told that they will give him no idea whatever of what has really been going on in the science. If he asks whether he should read one of the classic books by a linguist, such as Leonard Bloomfield's Language (New York, 1933), he is told that in parts it is excruciatingly hard to read, and that it is out of date anyhow. Having been rebuffed on both points, all but the most heroic language teachers will give the matter up then and there. Linguists will then go on muttering about people who don't want to learn about what they are teaching, and language teachers will go on muttering about people who have a science so extraordinary that it can't be explained to outsiders.

In 1946, modern foreign language instruction in the College of Arts and Sciences, Cornell University, underwent a drastic reorganization. The former departments of German and Romance Languages became departments of German and Romance Literatures; all language teaching as such (together with the teaching of philology and linguistics) was placed in the hands of a new Division of Modern Languages. The new program was quite frankly experimental: it was to be an attempt to adapt to the college situation the wartime experiences in teaching foreign languages to members of the armed forces. A grant to cover initial expenses was generously made by the Rockefeller Foundation. Within five years a faculty committee was to evaluate the new program and to recommend its continuation, revision, or abolishment.

“There is a wooded place in the midst of a vast wilderness and at the center of the peoples to whom we are preaching. There we have placed a group of monks living under the rule of St. Benedict, who are building a monastery.” So writes St. Boniface, in the year 751, to Pope Zacharias. Several years earlier Boniface had sent his favorite pupil, Sturm, into the forest of Bochonia to find a suitable location for a monastery. The site they finally agreed upon was a place called Eichloh, on the banks of the river Fulda. Here the monastery was dedicated in 744. So pleased was Boniface with this haven in the wilderness that he, born an Anglo-Saxon from Wessex, adds in his letter to Pope Zacharias: “Here I am proposing, with your kind permission, to rest my age-worn body for a little time and after my death to be buried here.”