Road Warriors: Fostering Object-Learner Assemblages Through a Social Context of Embodied Learning

This study investigates how adults informally learn through engaging with the object of their bicycles in the social context of the sport of amateur road racing, and explores how this learning has shaped their individual and social identities

Max Kaemper’s Unique Selection of Place Names for His 1908 Map of Mammoth Cave

In this paper we present Max Kaemper’s unique selection of Place Names for his 1908 map of Mammoth Cave. He realized the importance of Place Names and they became a feature on his map. His sensitive selection of Place Names provides a greater cultural emphasis, when compared to the previous maps

Disordered, stretched, and semiflexible biopolymers in two dimensions

We study the effects of intrinsic sequence-dependent curvature for a two dimensional semiflexible biopolymer with short-range correlation in intrinsic curvatures. We show exactly that when not subjected to any external force, such a system is equivalent to a system with a well-defined intrinsic curvature and a proper renormalized persistence length. We find the exact expression for the distribution function of the equivalent system. However, we show that such an equivalent system does not always exist for the polymer subjected to an external force. We find that under an external force, the effect of sequence-disorder depends upon the averaging order, the degree of disorder, and the experimental conditions, such as the boundary conditions. Furthermore, a short to moderate length biopolymer may be much softer or has a smaller apparent persistent length than what would be expected from the "equivalent system". Moreover, under a strong stretching force and for a long biopolymer, the sequence-disorder is immaterial for elasticity. Finally, the effect of sequence-disorder may depend upon the quantity considered

The effective length of columns in multi-storey frames

Codes of practice rely on the effective length method to assess the stability of multi-storey frames. The effective length method involves isolating a critical column within a frame and evaluating the rotational and translational stiffness of its end restraints, so that the critical buckling load may be obtained.The non-contradictory complementary information (NCCI) document SN008a [1] to BS EN 1993-1 [2] provides erroneous results in certain situations because it omits the contribution made to the rotational stiffness of the end restraints by columns above and below, and to the translational stiffness of end restraints by other columns in the same storey.Two improvements to the method are proposed in this paper. First, the axial load in adjoining columns is incorporated into the calculation of the effective length. Second, a modification to the effective length ratio is proposed that allows the buckling load of adjacent columns to be considered. The improvements are shown to be effective and consistently provide results within 2% of that computed by structural analysis software, as opposed to the up to 80% discrepancies seen using the NCCI [1]

Inverse problem for the Landau-Zener effect

We consider the inverse Landau-Zener problem which consists in finding the energy-sweep functions W(t)=E1(t)-E2(t) resulting in the required time dependences of the level populations for a two-level system crossing the resonance one or more times during the sweep. We find sweep functions of particular forms that let manipulate the system in a required way, including complete switching from the state 1 to the state 2 and preparing the system at the exact ground and excited states at resonance.Comment: 7 EPL pages, 6 figure

The History and Conservation of Saltpeter Works in Mammoth Cave, Kentucky

Remains of the saltpeter mining operation in Mammoth Cave are a significant feature of several cave tours and figure prominently in the history of cave use. We undertook a comprehensive review of existing historical descriptions and recent archaeological investigations to construct the most reasonable account of how the saltpeter operation worked and assess its current conditions. At least three types of saltpeter vats were constructed in the cave reflecting an increase in the size of the operation and efficiency of processing sediments over time. Remains of three pump towers are also found in the cave in various states of preservation. The water pipe system was mostly dismantled, but archaeological evidence indicates its most probable route through the cave. We recommend more thorough documentation of existing remains, conservation efforts to preserve existing remains, better interpretative signage, and possibly repair or replication of damaged or missing components to further enhance public interpretation

The UNSW Extrasolar Planet Search: Methods and First Results from a Field Centred on NGC 6633

We report on the current status of the University of New South Wales Extrasolar Planet Search project, giving details of the methods we use to obtain millimagnitude precision photometry using the 0.5m Automated Patrol Telescope. We use a novel observing technique to optimally broaden the PSF and thus largely eliminate photometric noise due to intra-pixel sensitivity variations on the CCD. We have observed 8 crowded Galactic fields using this technique during 2003 and 2004. Our analysis of the first of these fields (centred on the open cluster NGC 6633) has yielded 49 variable stars and 4 shallow transit candidates. Follow-up observations of these candidates have identified them as eclipsing binary systems. We use a detailed simulation of our observations to estimate our sensitivity to short-period planets, and to select a new observing strategy to maximise the number of planets detected.Comment: 16 pages, 9 figures, version published in MNRAS Updated figures, references, and additional discussion in section

Symmetric eikonal model for projectile-electron excitation and loss in relativistic ion-atom collisions

At impact energies $\stackrel{>}{\sim}1$ GeV/u the projectile-electron excitation and loss occurring in collisions between highly charged ions and neutral atoms is already strongly influenced by the presence of atomic electrons. In order to treat these processes in collisions with heavy atoms we generalize the symmetric eikonal model, used earlier for considerations of electron transitions in ion-atom collisions within the scope of a three-body Coulomb problem. We show that at asymptotically high collision energies this model leads to an exact transition amplitude and is very well suited to describe the projectile-electron excitation and loss at energies above a few GeV/u. In particular, by considering a number of examples we demonstrate advantages of this model over the first Born approximation at impact energies $\sim 1$--30 GeV/u, which are of special interest for atomic physics experiments at the future GSI facilities.Comment: 14 pages, 5 figure