600 a Current Leads with Dry and Compact Warm Terminals

For the LHC magnet test benches 26 pairs of conventional helium vapour-cooled 600 A current leads are required. The first pair of 600 A current leads has been designed and built by industry and tested at CERN. The main component of the lead is the heat exchanger, which consists of two concentric copper pipes. Special attention was also given to the design of the warm terminal in order to avoid any condensation and to resist at an electrical test of 2 kV. The paper describes construction details and compares calculated and measured values of the main parameters

Holding the wheel in passenger cars in countries with driving on the right and left side depending on the driver’s side preference

ArticleThis paper deals with the assessment of the differences in how passenger car drivers hold a steering wheel with left and right-side steering in specific driving modes. The findings are compared to the generally-accepted optimal position in terms of active and passive safety, as well as long-term effects on the health of the driver. The research described in this work was conducted on a sample of randomly selected drivers in the Czech Republic, the UK and Australia using electronic questionnaires. The data was then subjected to a statistical evaluation, which looked primarily at the difference between the way in which the steering wheel was held in countries with driving on the right and driving on the left. Another parameter for statistical data evaluation was the used side preference of individual drivers. On the basis of a statistical evaluation of the obtained data, it was found that there is a difference in the way the steering wheel is held in the assessed traffic situations between drivers driving on the right and drivers driving on the left. The results of this work can be used in the design process of passenger car cabins, in particular in the field of adaptation of the control devices of particular models to the needs of drivers in individual countries based on the type of traffic. The results of the work point out the necessity to make innovations in the design of passenger car cabins with regard to the type of traffic in which the vehicle will be operated, which could lead to a better application of innovations, and thereby better possibilities of positively influencing traffic safety and the health of drivers

Asymmetrical dynamics of voltage spread in retinal horizontal cell networks

This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Lateral voltage spread in electrically coupled retinal horizontal cell networks is the substrate of center-surround antagonism in bipolar and ganglion cells. We studied its spatial and temporal properties in more detail in turtle L1 horizontal cells by using a contrast border as light stimulus. Experimental data were contrasted with expectations from a linear continuum model to specify the impact of nonlinearities. The assumptions for the diffusion term of the continuum model were justified by neurobiotin labeling. Measured voltage spread revealed two different length constants Λ+ and Λ0, under illuminated and nonilluminated regions of the retina, respectively, as predicted by the linear model. Length constants in the illuminated region showed strong temporal dynamics. For the initial phase of the horizontal cell responses Λ+ was larger than Λo. This was also in accordance with the model. Right at the peak of the response, however, Λ+ dropped below Λo and did not change any more. It is this temporal reversal of asymmetry in voltage spread and not the decrease of Λ+ itself that is lacked by the linear model. The observed independence of the mean ratio Λ+/Λo from light intensity in both the peak and the plateau phases of horizontal cell responses contradicts the linear assumption, too. These two effects have to be addressed to local nonlinearities in the horizontal cell network like a negative feedback loop from photoreceptors and/or voltage-dependent conductances. Due to the failure of the linear model, firm conclusions about the membrane resistance and the coupling resistance of the horizontal cell network cannot be drawn from length constant measurements.Peer Reviewe

A Geometrical Characterization of the Twin Paradox and its Variants

The aim of this paper is to provide a logic-based conceptual analysis of the twin paradox (TwP) theorem within a first-order logic framework. A geometrical characterization of TwP and its variants is given. It is shown that TwP is not logically equivalent to the assumption of the slowing down of moving clocks, and the lack of TwP is not logically equivalent to the Newtonian assumption of absolute time. The logical connection between TwP and a symmetry axiom of special relativity is also studied.Comment: 22 pages, 3 figure