Motives to Assist and Reasons to Assist: the Case of Global Poverty

The principle of assistance says that the global rich should help the global poor because they are able to do so, and at little cost. The principle of contribution says that the rich should help the poor because the rich are partly to blame for the plight of the poor. This paper explores the relationship between the two principles and offers support for one version of the principle of assistance. The principle of assistance is most plausible, the paper argues, when formulated so as to identify obligations that arise from the needs of particular identifiable members of the global poor, not from impersonal rules or values. Under that formulation, the principle can explain why knowledge of the circumstances faced by individual members of the global poor can have such a marked effect upon the willingness of the global rich to provide help, and can offer a better grounded motivational basis for helping the global poor. These are real advantages, the paper argues, and ones that cannot be matched by stories that focus upon the ways in which the global rich contribute to global poverty

Accuracy of sex determination for northeastern Pacific Ocean thornyheads (Sebastolobus altivelis and S. alascanus)

Determining the sex of thornyheads (Sebastolobus alascanus and S. altivelis) can be difficult under field conditions. We assessed our ability to correctly assign sex in the field by comparing results from field observations to results obtained in the laboratory through both macroscopic and microscopic examination of gonads. Sex of longspine thornyheads was more difficult to determine than that of shortspine thornyheads and correct determination of sex was signif icantly related to size. By restricting the minimum size of thornyheads to 18 cm for macroscopic determination of sex we reduced the number of fish with misidentified sex by approximately 65%

Friction Reduction in a Revolute Joint by the Use of Axial High-Frequency Excitation

While downscaling gains importance in many technical components, accuracy must increase as well. This is a challenge especially for dry bearings with small tolerances. To suppress friction induced phenomena like stick-slip-motions or break-away-effects, superposed oscillations can be used to specifically influence the friction characteristic. In this context, the present contribution deals with a friction revolute joint with axial high-frequency excitation to reduce friction torque. There is a special focus on the heat generation and its interaction with the system dynamics

Quenching friction‐induced oscillations in multibody‐systems by the use of high‐frequency excitation

Dry friction can be a cause of undesired self-excited oscillations. One way to suppress this underlying mechanism is the superposition of high-frequency vibrations whereby the effective friction characteristics is changed and a quasi-equilibrium can be stabilized. This damping effect is analyzed in detail for single-degree-of-freedom systems [1] and experiments and simulations show a good accordance [2]. In this work, the analytical approach from [1] is used to analyze the stabilizing effect of superposed oscillations for a two-degree-of-freedom system subject to friction