Brave New World: Can We Engineer a Better Start for Freshers?

Abstract - The crucial importance of first experiences in shaping future success has been widely acknowledged. Creating the best foundations in large cohorts of students from diverse backgrounds presents special problems of its own. But a secure foundation can enhance student achievement and improve retention – and the students may even have fun too. Research has suggested that building learning communities can enhance student engagement and achievement. This paper examines how introducing non-technical activities can establish sound foundations for a university career by a) addressing objectives in the wider curriculum and b) promoting non-technical skills and experience of group working. A set of changes introduced to five degree cohorts in our academic school were designed to complement enhancements to our technical curriculum introduced during many years of debate and consideration. The changes have impacted upon generic and technical educational experiences. The paper presents an evaluation of the programme of changes through two iterations from the perspective of both faculty and student

Hybrid geared traction transmissions

The basic configuration of geared traction drives, geometric and structural factors to be considered in their construction, and current work on hybrid helicopter transmissions rated at 500 and 3000 hp are discussed

Neel order in square and triangular lattice Heisenberg models

Using examples of the square- and triangular-lattice Heisenberg models we demonstrate that the density matrix renormalization group method (DMRG) can be effectively used to study magnetic ordering in two-dimensional lattice spin models. We show that local quantities in DMRG calculations, such as the on-site magnetization M, should be extrapolated with the truncation error, not with its square root, as previously assumed. We also introduce convenient sequences of clusters, using cylindrical boundary conditions and pinning magnetic fields, which provide for rapidly converging finite-size scaling. This scaling behavior on our clusters is clarified using finite-size analysis of the effective sigma-model and finite-size spin-wave theory. The resulting greatly improved extrapolations allow us to determine the thermodynamic limit of M for the square lattice with an error comparable to quantum Monte Carlo. For the triangular lattice, we verify the existence of three-sublattice magnetic order, and estimate the order parameter to be M = 0.205(15).Comment: 4 pages, 5 figures, typo fixed, reference adde

Cosmology of the Next-to-Minimal Supersymmetric Standard Model

We discuss the domain wall problem in the Next-to-Minimal Supersymmetric Standard Model, with particular attention to the usual solution of explicit breaking of the discrete symmetry by non-renormalisable operators. This ``solution'' leads to a contradiction between the requirements of cosmology and those of avoiding the destabilisation of the hierarchy.Comment: 6 pages LaTeX, needs sprocl.sty (included at end) Talk presented by P.L. White at Valencia 9

Topography of Spin Liquids on a Triangular Lattice

Spin systems with frustrated anisotropic interactions are of significant interest due to possible exotic ground states. We have explored their phase diagram on a nearest-neighbor triangular lattice using the density-matrix renormalization group and mapped out the topography of the region that can harbor a spin liquid. We find that this spin-liquid phase is continuously connected to a previously discovered spin-liquid phase of the isotropic $J_1\!-\!J_2$ model. The two limits show nearly identical spin correlations, making the case that their respective spin liquids are isomorphic to each other.Comment: Accepted to PRL; 5 p., 11+ p. supplemental; main text is longer than the accepted versio

Disorder-Induced Mimicry of a Spin Liquid in YbMgGaO4_4

We suggest that a randomization of the pseudo-dipolar interaction in the spin-orbit-generated low-energy Hamiltonian of YbMgGaO$_4$ due to an inhomogeneous charge environment from a natural mixing of Mg$^{2+}$ and Ga$^{3+}$ can give rise to orientational spin disorder and mimic a spin-liquid-like state. In the absence of such quenched disorder, $1/S$ and density matrix renormalization group calculations both show robust ordered states for the physically relevant phases of the model. Our scenario is consistent with the available experimental data and further experiments are proposed to support it.Comment: 5+ main text, 7+ supplemental, text asymptotically close to PR

Concept for a large master/slave-controlled robotic hand

A strategy is presented for the design and construction of a large master/slave-controlled, five-finger robotic hand. Each of the five fingers will possess four independent axes each driven by a brushless DC servomotor and, thus, four degrees-of-freedom. It is proposed that commercially available components be utilized as much as possible to fabricate a working laboratory model of the device with an anticipated overall length of two-to-four feet (0.6 to 1.2 m). The fingers are to be designed so that proximity, tactile, or force/torque sensors can be imbedded in their structure. In order to provide for the simultaneous control of the twenty independent hand joints, a multilevel master/slave control strategy is proposed in which the operator wears a specially instrumented glove which produces control signals corresponding to the finger configurations and which is capable of conveying sensor feedback signals to the operator. Two dexterous hand master devices are currently commercially available for this application with both undergoing continuing development. A third approach to be investigated for the master control mode is the use of real-time image processing of a specially patterned master glove to provide the respective control signals for positioning the multiple finger joints

Spin injection dependent metamagnetic transition

We define the metamagnetic phase transition of itinerant electrons controlled by the spin injection mechanism. The current flow between a ferromagnetic metal and a metamagnetic metal produces the non-equilibrium shift of chemical potential for spin up and spin down electrons that acts as an effective magnetic field driving the metamagnetic transition.Comment: 6 pages, 3 figure