An asymptotic membrane-like theory for long-wave motion in a pre-stressed elastic plate

An asymptotically consistent two-dimensional theory is developed to help elucidate dynamic response in finitely deformed layers. The layers are composed of incompressible elastic material, with the theory appropriate for long-wave motion associated with the fundamental mode and derived in respect of the most general appropriate strain energy function. Leading-order and refined higher-order equations for the mid-surface deflection are derived. In the case of zero normal initial static stress and in-plane tension, the leading-order equation reduces to the classical membrane equation, with its refined counterpart also being obtained. The theory is applied to a one-dimensional edge loading problem for a semi-infinite plate. In doing so, the leading- and higher-order governing equations are used as inner and outer asymptotic expansions, the latter valid within the vicinity of the associated quasi-front. A solution is derived by using the method of matched asymptotic expansions

World Database of Terrestrial Carbonate Spring Hydrochemistry

A Database of Hydrochemical Data for springs, rivers, lakes, swamps and other sites in which calcium carbonate is being actively deposited. This dataset is linked to an article by Rogerson, Pedley, Kelham and Wadhawan, currently In Review for the journal Earth Surface Dynamics. The dataset will be added to over time as additional data is gathered

Overlapping murmurs

Overlapping Murmurs is an ambient sound installation presented as part of the 'INDELIBLE' exhibition at Waikato Museum. Overlapping Murmurs is a collaboration between Jeremy Mayall, Kent Macpherson, Haco, Horomona Horo, Reuben Bradley, and Megan Rogerson-Berry. It is designed to provide an overall accompaniment to the show, whilst also being a deconstruction and re-working of elements from the Where We Overlap recording sessions

A dynamic explanation for the origin of the western Mediterranean organic-rich layers

The eastern Mediterranean sapropels are among the most intensively investigated phenomena in the paleoceanographic record, but relatively little has been written regarding the origin of the equivalent of the sapropels in the western Mediterranean, the organic-rich layers (ORLs). ORLs are recognized as sediment layers containing enhanced total organic carbon that extend throughout the deep basins of the western Mediterranean and are associated with enhanced total barium concentration and a reduced diversity (dysoxic but not anoxic) benthic foraminiferal assemblage. Consequently, it has been suggested that ORLs represent periods of enhanced productivity coupled with reduced deep ventilation, presumably related to increased continental runoff, in close analogy to the sapropels. We demonstrate that despite their superficial similarity, the timing of the deposition of the most recent ORL in the Alboran Sea is different than that of the approximately coincident sapropel, indicating that there are important differences between their modes of formation. We go on to demonstrate, through physical arguments, that a likely explanation for the origin of the Alboran ORLs lies in the response of the western Mediterranean basin to a strong reduction in surface water density and a shoaling of the interface between intermediate and deep water during the deglacial period. Furthermore, we provide evidence that deep convection had already slowed by the time of Heinrich Event 1 and explore this event as a potential agent for preconditioning deep convection collapse. Important differences between Heinrich-like and deglacial-like influences are highlighted, giving new insights into the response of the western Mediterranean system to external forcing

Towards A Decolonized Radical Southern African Geography

A Geographical Education Magazine article.Non-conventional approaches to southern African geography are a recent phenomenon forming a tiny portion of contemporary research (Beacon and Rogerson 1901; Smith 1982; Crush and Rogerson 1933) and the call for a 'decolonization of the existing colonial geographies concerning southern Africa' (Crush, Reitsma and Rogerson 1982, p. 197) deserves serious consideration by the region's geographers. Southern African geographers, like many other scholars in the region, have traditionally tended to be 'mere imitators and burglars of other people's methodologies and research techniques' (Avandele 1982, p. 172). In decolonizing southern African geography, a departure from this tradition is required for not even a mechanical transfer of radical geography as it has emerged in the West will do; a critical perspective which leaves room for independent reflection and avoiding the rigidity and theoreticism threatening radical geography as a whole is necessary; and ultimately the region's geographic lore has to be authored and acted in southern Africa

Hypomyces chrysospermus

Parasitic on Boletaceae. Found under Tsuga, Acer, and Betula. 8-12 cm. Subiculum white, powdery, fluffy, turning yellow with age, covering pileus, stipe, and hymenium on fully colonized specimens. Inner flesh soft, occasionally displaying guttation. Most host specimens unrecognizable with the exception of one partially colonized Leccinum spp. (pictured). There are 10 recognized species of Boleticolous Hypomyces. The bright yellow coloration of older specimens is consistent with descriptions of H. chrysospermus, but microscopic analysis is required for confirmation of ID (Rogerson and Samuels 1994). H. chrysospermus is the telemorphic stage of this unusual ascomycete, while the anamorphic stage is Sepedonium chrysospermus (Rogerson and Samuels 1989). This distinction represents a vestige of dual nomenclature within mycology (Hawksworth 2011). ID number: 20.23.02.2021https://orb.binghamton.edu/macrofungi_eastbrookvalley/1045/thumbnail.jp

Non-principal surface waves in deformed incompressible materials

The Stroh formalism is applied to the analysis of infinitesimal surface wave propagation in a statically, finitely and homogeneously deformed isotropic half-space. The free surface is assumed to coincide with one of the principal planes of the primary strain, but a propagating surface wave is not restricted to a principal direction. A variant of Taziev’s technique [R.M. Taziev, Dispersion relation for acoustic waves in an anisotropic elastic half-space, Sov. Phys. Acoust. 35 (1989) 535–538] is used to obtain an explicit expression of the secular equation for the surface wave speed, which possesses no restrictions on the form of the strain energy function. Albeit powerful, this method does not produce a unique solution and additional checks are necessary. However, a class of materials is presented for which an exact secular equation for the surface wave speed can be formulated. This class includes the well-known Mooney–Rivlin model. The main results are illustrated with several numerical examples

The employment of nations — a primer

This paper examines low-frequency movements in employment in a cross-section of industrialized countries for the period 1960–95, using both aggregate and disaggregated data. It documents nine stylized facts about cross-country variations in employment.Employment (Economic theory)

Indeliable exhibition: Yellow river boat (2018): Trap (2018)

This exhibition is one of two that make up a cultural and artistic exchange project with Xi'an Art Museum, Xi'an City, Shaanxi Province, China; Waikato Museum, Hamilton, NZ; and Wintec researchers (Hamilton, NZ). Themes of exchange, community, identity and location were explored by the various practitioners involved in the project. These two sculptural works examine cultural practices of food gathering in relationship to community

Hypomyces hyalinus

Parasitic on Amanitas (Rogerson & Samuels 1994). Likely A. rubescens and A. frostiana on our specimens. Found under Pinus and Tsuga. The telemorphic form of this fungus deforms the host Amanita, resulting in a bulbous, occasionally shaggy stipe, a small subglobose cap, and a white subiculum covering the entire fruiting body. On Amanita rubescens, the subiculum occasionally retains pinkish brown staining from the host, between 10 and 20 cm high. On Amanita frostiana, coloration is tawny on the stipe and yellow on the pileus. Occasionally universal veil remnants (“warts”) are still visible beneath subiculum on both hosts. Specimens recognized by coloration, stature, and proximity to non parasitized fruiting bodies. No ascospore germination nor consistently associated animorphs have yet been observed (Rogerson and Samuels 1994). ID number: 20.23.03.2021https://orb.binghamton.edu/macrofungi_eastbrookvalley/1046/thumbnail.jp