Development of a contra-rotating tidal current turbine and analysis of performance

A contra-rotating marine current turbine has a number of attractive features: nearzero reactive torque on the support structure, near-zero swirl in the wake, and high relative inter-rotor rotational speeds. Modified blade element modelling theory has been used to design and predict the characteristics of such a turbine, and a model turbine and test rig have been constructed. Tests in a towing tank demonstrated the feasibility of the concept. Power coefficients were high for such a small model and in excellent agreement with predictions, confirming the accuracy of the computational modelling procedures. Highfrequency blade loading data were obtained in the course of the experiments. These show the anticipated dynamic components for a contra-rotating machine. Flow visualization of the wake verified the lack of swirl behind the turbine. A larger machine is presently under construction for sea trials

Negotiating About Charges and Pleas: Balancing Interests and Justice

There is a worldwide movement towards alternatives to judicial decision-making for legal disputes. In the domain of criminal sentencing, in Western countries more than 95 % of cases are guilty pleas, with many being decided by negotiations over charges and pleas, rather than a decision being made after a judge or jury has heard all relevant evidence in a trial. Because decisions are being made, and people incarcerated on the basis of negotiations, it is important that such negotiations be just and fair. In this paper we discuss issues of fairness in plea-bargaining and how we can develop systems to support the process of plea and charge negotiation. We discuss how we are using Toulmin’s theory of argumentation and Lodder and Zeleznikow’s model of online dispute resolution to develop just plea bargaining systems. A specific investigation of the process of charge mentions is discussed

Upper critical field in layered superconductors

The theoretical statements about a restoration of a superconductivity at magnetic fields higher than the quasiclassical upper critical field and a reentrance of superconductivity at temperatures $T_c(H)\approx T_c(0)$ in the superconductors with open Fermi surfaces are reinvestigated taking into account a scattering of quasiparticles on the impurities. The system of integral equations for determination of the upper critical field parallel to the conducting planes in a layered conventional and unconventional superconductors with impurities are derived. The $H_{c2}(T)$ values for the "clean" case in the Ginzburg-Landau regime and at any temperature in the "dirty" case are found analytically. The upper limit of the superconductor purity when the upper critical field definately has a finite value is established.Comment: 10 page

Barriers to the use of a diagnostic oral microbiology laboratory by general dental practitioners

OBJECTIVE: To identify barriers on the use of diagnostic microbiology facilities in general dental practice. DESIGN: A cross-sectional survey using a postal questionnaire. SETTING: Primary/secondary care interface between the diagnostic oral microbiology laboratory, University of Glasgow Dental Hospital and School, Glasgow and dental practitioners within the surrounding health boards, 1998. SUBJECTS: All GDPs (797) within Argyll and Clyde, Ayrshire and Arran, Lanarkshire and Greater Glasgow Health Boards. MAIN OUTCOME MEASURES: The responses were expressed as both absolute and relative frequencies. RESULTS: Responses were received from 430 (55%). The most frequent reason for failure to use the service was lack of information, with more than half of the respondents claiming to be unaware of the facility. Lack of request forms and sampling equipment were also viewed as barriers to using the service. CONCLUSIONS: The laboratory is failing to successfully communicate its role in addressing the growing burden of antibiotic resistance in the community and must be more proactive in encouraging appropriate use and increasing accessibility of the service to GDPs

Magnetoresistance of Highly Correlated Electron Liquid

The behavior in magnetic fields of a highly correlated electron liquid approaching the fermion condensation quantum phase transition from the disordered phase is considered. We show that at sufficiently high temperatures $T\geq T^*(x)$ the effective mass starts to depend on $T$, $M^*\propto T^{-1/2}$. This $T^{-1/2}$ dependence of the effective mass at elevated temperatures leads to the non-Fermi liquid behavior of the resistivity, $\rho(T)\propto T$ and at higher temperatures $\rho(T)\propto T^{3/2}$. The application of a magnetic field $B$ restores the common $T^2$ behavior of the resistivity. The effective mass depends on the magnetic field, $M^*(B)\propto B^{-2/3}$, being approximately independent of the temperature at $T\leq T^*(B)\propto B^{4/3}$. At $T\geq T^*(B)$, the $T^{-1/2}$ dependence of the effective mass is re-established. We demonstrate that this $B-T$ phase diagram has a strong impact on the magnetoresistance (MR) of the highly correlated electron liquid. The MR as a function of the temperature exhibits a transition from the negative values of MR at $T\to 0$ to the positive values at $T\propto B^{4/3}$. Thus, at $T\geq T^*(B)$, MR as a function of the temperature possesses a node at $T\propto B^{4/3}$.Comment: 7 pages, revtex, no figure

Jacobi structures revisited

Jacobi algebroids, that is graded Lie brackets on the Grassmann algebra associated with a vector bundle which satisfy a property similar to that of the Jacobi brackets, are introduced. They turn out to be equivalent to generalized Lie algebroids in the sense of Iglesias and Marrero and can be viewed also as odd Jacobi brackets on the supermanifolds associated with the vector bundles. Jacobi bialgebroids are defined in the same manner. A lifting procedure of elements of this Grassmann algebra to multivector fields on the total space of the vector bundle which preserves the corresponding brackets is developed. This gives the possibility of associating canonically a Lie algebroid with any local Lie algebra in the sense of Kirillov.Comment: 20 page