The improvement of zinc electrodes for electrochemical cells Quarterly report no. 2, Sep. 4 - Dec. 4, 1965

Growth parameters of mossy and crystalline dendrites applied to manufacture and handling of silver-zinc batterie

Improved alkaline electrochemical cell

Addition of lead ions to electrolyte suppresses zinc dendrite formation during charging cycle. A soluble lead salt can be added directly or metallic lead can be incorporated in the zinc electrode and allowed to dissolve into the electrolyte

High Power Semiconductor Devices and Solid State Switches for Pulsed Discharge Applications

Based on long term experience, collected mainly with military applications like Rail Guns and Active Armour, a range of optimized semiconductor devices for pulsed applications was developed by ABB Switzerland Ltd and described in this presentation. The presented devices are optimized for pulsed discharge and fit very well for switching the short but high electrical power demand used for magnetic forming. Devices are available in different versions with silicon wafer diameters up to 120 mm and blocking voltages of over 6500V. Because of the different application requirements a differentiation is made in device technology. Depending on the discharge circuit, devices for low, medium, or high di/dt can be selected and the difference in advantages and disadvantages between both technologies will be described. To minimize the inductance between switching device and freewheeling diode, ABB can integrate this diode monolithic on the switching wafer. These so called reverse conducting devices are very common for magnetic forming applications. Thyristor structures are commercially available up to 8500V with 120 mm silicon wafers and GTO-like structures are available up to 4500V with 91 mm silicon wafers. For higher voltages or higher currents a combination of devices in series and/or parallel connection is required. The presentation will also describe the evolution of complete discharge switching modules in the range of 10kV / 50 kJ, a large discharge system of 21kV / 200kA, and a newly designed high current switch in the range of 15kV / 3MJ. The solid state switch solutions offered today and those shown in the presentation are based on a standard platform of components existing already for several years. For reliability reasons it is of great importance that the switch assemblies for high current pulsed applications are designed in cooperation with the device manufacturer who has in-depth knowledge of the switching behavior of the semiconductor components under pulsed conditions. The advantage of a complete switch assembly is that the whole unit can be tested under application conditions. ABB has a test capability up to 65 kV and 85 kJ stored energy

Nonlinear Dynamics of Composite Fermions in Nanostructures

We outline a theory describing the quasi-classical dynamics of composite fermions in the fractional quantum Hall regime in the potentials of arbitrary nanostructures. By an appropriate parametrization of time we show that their trajectories are independent of their mass and dispersion. This allows to study the dynamics in terms of an effective Hamiltonian although the actual dispersion is as yet unknown. The applicability of the theory is verified in the case of antidot arrays where it explains details of magnetoresistance measurements and thus confirms the existence of these quasiparticles.Comment: submitted to Europhys. Lett., 4 pages, postscrip

Thep-Intersection Subgroups in Quasi-Simple and Almost Simple Finite Groups

AbstractLetpbe a fixed prime andGa finite group. A proper subgroupX<Gis called ap-intersection subgroupifX∩Xgis ap-group for eachg∈G\X, butXis not ap-group. In this paper we classify thep-intersection subgroups in the quasi-simple and almost simple finite groups

The improvement of zinc electrodes for electrochemical cells Quarterly report no. 3, 5 Dec. 1965 - 4 Mar. 1966

Dendrite deposits on zinc electrodes of electrochemical cell and substrate effect

On the generalized Davenport constant and the Noether number

Known results on the generalized Davenport constant related to zero-sum sequences over a finite abelian group are extended to the generalized Noether number related to the rings of polynomial invariants of an arbitrary finite group. An improved general upper bound is given on the degrees of polynomial invariants of a non-cyclic finite group which cut out the zero vector.Comment: 14 page

Information Ethics Education for a Multicultural World

How can we prepare information systems students to face the ethical challenges of a globalized world? This paper describes a three-step approach for addressing these challenges. First, we have designed undergraduate and graduate information ethics courses that expand the range of learning of ethical theories beyond the traditional Western canon to include a wide spectrum of non-Western and feminist theories. Second, we have designed interactive cases for this course that adopt a collaborative learning approach where students work together in small groups by playing different roles that make interdependent decisions. Third, we deliver these cases via an educational simulation, making the approach scalable and transferable to other institutions across the country and around the world. The data for this study includes textual answers from end-of-semester questionnaires completed by 101 undergraduate and graduate students during four information ethics courses that included use of the simulation. Data was analyzed using thematic analysis, focusing on the multicultural and global dimensions of student learning. Five themes emerged from data collected in the four courses: Learning about a Diverse Range of Ethical Theories; Learning about how Ethical Theories are Related to Culture and Values; Relating International and Multicultural Dimensions to Understanding Oneself; Relating International and Multicultural Dimensions to Understanding Others; and Understanding the Role of Ethics and Culture in Information Systems Design and Use. Based on these results, the three-step approach developed in this study can be implemented across the country and around the world to ensure that students are prepared for the ethical challenges of a globalized world