Adolf Reinach: An Intellectual Biography

The essay provides an account of the development of Reinach’s philosophy of “Sachverhalte” (states of affairs) and on problems in the philosophy of law, leading up to his discovery of the theory of speech acts in 1913. Reinach’s relations to Edmund Husserl and to the Munich phenomenologists are also dealt with

The Person of Jesus Christ

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The rise of a native sun coral species on southern Caribbean coral reefs

In contrast with a general decline of Caribbean reef corals, a previously rare sun coral is increasing in abundance within shallow coral communities on Curaçao. This azooxanthellate scleractinian was identified as Cladopsammia manuelensis, which has an amphi‐Atlantic distribution. Over the last decade, C. manuelensis has increased abundance along the leeward coast of Curaçao (southern Caribbean) between depths of 4 and 30 m. This species was initially not noticed because it resembles the invasive coral Tubastraea coccinea, which was introduced to Curaçao from the Indo‐Pacific around 1940. However, in contrast to T. coccinea, C. manuelensis was previously only present on deeper reef sections (>70 m) of Caribbean reefs. Our observations illustrate how the sudden increase in abundance of a previously unnoticed, apparently cryptogenic species could result from natural dynamics on present‐day reefs, but also could easily be mistaken for an invasive species. The finding that deep reef sections can harbor species capable of colonizing shallower reef zones highlights the importance of thorough inventories of reef communities across large depth ranges, which can help us to discriminate between range increases of native species and the arrival of invasives

Composite Repairs To Cracked Metallic Components- Experiment and Theory

In this paper we show how the published literature reveals that the analytical solution for a composite repair to a cracked metallic plate is inconsistent with experimental data, and that the fibre bridging effect is often a second order effect. The result is that prediction of the effect of a composite repair on the structural integrity of cracked components repaired by an externally bonded composite repair is dramatically simplified

Electrically-assisted bikes: potential impacts on travel behaviour

This paper reports on a review of the European literature about the impacts of having an electrically-assisted bike available to use, together with results from a trial in the UK city of Brighton, where 80 employees were loaned an electrically-assisted bike for a 6–8 week period. In the Brighton trial, three-quarters of those who were loaned an e-bike used them at least once a week. Across the sample as a whole, average usage was in the order of 15–20 miles per week, and was accompanied by an overall reduction in car mileage of 20%. At the end of the trial, 38% participants expected to cycle more in the future, and at least 70%said that they would like to have an e-bike available for use in the future, and would cycle more if this was the case. This is consistent with the results of the European literature which shows that when e-bikes are made available, they get used; that a proportion of e-bike trips typically substitutes for car use; and that many people who take part in trials become interested in future e-bike use, or cycling more generall

Stability and transport of parallel velocity shear driven mode with negative magnetic shear

The linear and quasilinear behavior of the drift-like perturbation with a parallel velocity shear is studied in a sheared slab geometry. Full analytic studies show that when the magnetic shear has the same sign as the second derivative of the parallel velocity with respect to the radial coordinate, the linear mode may become unstable and turbulent momentum transport increases. On the other hand, when the magnetic shear has opposite sign to the second derivative of the parallel velocity, the linear mode is completely stabilized and turbulent momentum transport reduces

Numerical simulation of unconstrained cyclotron resonant maser emission

When a mainly rectilinear electron beam is subject to significant magnetic compression, conservation of magnetic moment results in the formation of a horseshoe shaped velocity distribution. It has been shown that such a distribution is unstable to cyclotron emission and may be responsible for the generation of Auroral Kilometric Radiation (AKR) an intense rf emission sourced at high altitudes in the terrestrial auroral magnetosphere. PiC code simulations have been undertaken to investigate the dynamics of the cyclotron emission process in the absence of cavity boundaries with particular consideration of the spatial growth rate, spectral output and rf conversion efficiency. Computations reveal that a well-defined cyclotron emission process occurs albeit with a low spatial growth rate compared to waveguide bounded simulations. The rf output is near perpendicular to the electron beam with a slight backward-wave character reflected in the spectral output with a well defined peak at 2.68GHz, just below the relativistic electron cyclotron frequency. The corresponding rf conversion efficiency of 1.1% is comparable to waveguide bounded simulations and consistent with the predictions of kinetic theory that suggest efficient, spectrally well defined radiation emission can be obtained from an electron horseshoe distribution in the absence of radiation boundaries.Publisher PD

Simulations of Electron Acceleration at Collisionless Shocks: The Effects of Surface Fluctuations

Energetic electrons are a common feature of interplanetary shocks and planetary bow shocks, and they are invoked as a key component of models of nonthermal radio emission, such as solar radio bursts. A simulation study is carried out of electron acceleration for high Mach number, quasi-perpendicular shocks, typical of the shocks in the solar wind. Two dimensional self-consistent hybrid shock simulations provide the electric and magnetic fields in which test particle electrons are followed. A range of different shock types, shock normal angles, and injection energies are studied. When the Mach number is low, or the simulation configuration suppresses fluctuations along the magnetic field direction, the results agree with theory assuming magnetic moment conserving reflection (or Fast Fermi acceleration), with electron energy gains of a factor only 2 - 3. For high Mach number, with a realistic simulation configuration, the shock front has a dynamic rippled character. The corresponding electron energization is radically different: Energy spectra display: (1) considerably higher maximum energies than Fast Fermi acceleration; (2) a plateau, or shallow sloped region, at intermediate energies 2 - 5 times the injection energy; (3) power law fall off with increasing energy, for both upstream and downstream particles, with a slope decreasing as the shock normal angle approaches perpendicular; (4) sustained flux levels over a broader region of shock normal angle than for adiabatic reflection. All these features are in good qualitative agreement with observations, and show that dynamic structure in the shock surface at ion scales produces effective scattering and can be responsible for making high Mach number shocks effective sites for electron acceleration.Comment: 26 pages, 12 figure

New Records of Deep-Water Cnidaria (Scleractinia & Antipatharia) from the Gulf of Mexico

Slxty·three species of azooxanthellate scleractinians and 26 species of antipatharians are recorded from the Gulf of Mexico. This report constitutes the first Inventory of Antipatharia within the geographic boundaries of the Gulf of Mexico whose southern limits are the Yucatan Straits to the south and the Florida Straits to the east. Thirteen range extensions of azooxanthellate species of the Order Scleractinia, and 28 species of the Order Antipatharia are reported. With respect to new records, we report four new records of azooxanthelate scleractinians and six new records of antipatharians from the outer continental shelf. One of the species, Slbopathes macrosplna Opresko, 1993, represents a new species In the western Atlantic region and appears related to Sibopathes gephura Van Pesch, 1914. The Gulf scleractinian fauna constitutes 54% of those known from the western Atlantic; the antipatharian fauna constitutes 93% of the western Atlantic fauna. These two groups are most diverse (55-56 species) in the regions of the Gulf adjacent to the Caribbean Sea and Atlantic Ocean (subdivisions I and VI). Diversity gradually decreases towards the western Gulf. Only six species are known from subdivision IV (east Mexico shelf and slope) and 23 species are recorded from subdivision V (Campeche Bank, Mexico)