Gaussian Tunneling Model of c-Axis Twist Josephson Junctions

We calculate the critical current density $J^J_c$ for c-axis Josephson tunneling between identical high temperature superconductors twisted an angle $\phi_0$ about the c-axis. We model the tunneling matrix element squared as a Gaussian in the change of wavevector q parallel to the junction, $<|t({\bf q})|^2>\propto\exp(-{\bf q}^2a^2/2\pi^2\sigma^2)$. The $J^J_c(\phi_0)/J^J_c(0)$ obtained for the s- and extended-s-wave order parameters (OP's) are consistent with the Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ data of Li {\it et al.}, but only for strongly incoherent tunneling, $\sigma^2\ge0.25$. A $d_{x^2-y^2}$-wave OP is always inconsistent with the data. In addition, we show that the apparent conventional sum rule violation observed by Basov et al. might be understandable in terms of incoherent c-axis tunneling, provided that the OP is not $d_{x^2-y^2}$-wave.Comment: 6 pages, 6 figure

Aandrijfsysteem voor een gereedschap of een vehikel

Chain link (4) couplings (5) are permanent magnets with the same polarity. Their motion induces current in induction coils (6). Magnetic bearings on both sides align the chain with the coils. Coils are connected in parallel and charge a battery. Battery power can provide motor assistance to the chain drive.Industrial Design Engineerin

Energy matching: Key towards the design of sustainable photovoltaic powered products

The starting point of this dissertation is the observation that today a vast amount of 'PV powered' products are already on the market. However, in these PV powered products quite often the choice of PV cells seems random and PV cells function mostly as add-on units to give the product a 'green' energy image. Because of this 'add-on' approach, the PV cells remain foreign bodies which are not well-integrated into the total product design. As a result in today's PV powered products often a sub-optimal matching between the PV cell characteristics, energy storage and the product user contexts. Therefore, the keyword to obtain a mature and sustainably designed PV powered product will be matching. As a result the research question is formulated as: What systematic matching can be achieved between the elements and interfaces of the energy chain of photovoltaic powered mobile/wireless products? The emphasis of this dissertation will be on the optimal matching in the energy chain of PV powered products. For this purpose, an Energy Matching Model of the energy chain is developed. This dissertation will present how, why and under what circumstances a novel Energy Matching Model and associated Figure of Matching algorithm can support industrial designers in developing sustainable photovoltaic powered products. This PhD research project is executed within the framework of the SYN-Energy program which explores the feasibility of a transition towards the use of photovoltaic (PV) cells in consumer and professional products. This program is a part of the 'Energy Research Stimulation Program' of the Netherlands Organisation for Scientific Research (NWO).Industrial Design Engineerin

Battery, especially for portable devices, has an anode containing silicon

The anode (2) contains silicon. A battery with a silicon-containing anode is claimed. An Independent claim is also included for a method used to make the battery, comprising the doping of a silicon substrate (1) with charge capacity-increasing material (preferably boron, phosphorous or arsenic), etching the doped substrate layer in order to increase its porosity, and applying a cathode (3) in the form of a lithium oxide compound onto the resulting anode and applying an electrolyte (4) to the anode-facing side of the cathode.Industrial Design Engineerin

Towards a more efficient energy use in photovoltaic powered products

This paper analyzes the energy saving and power management solutions necessary to improve the energy consumption efficiency in photovoltaic powered products. Important in the design of such products is not only the energy supply optimization required to deliver the actual energy to fulfil their function, but also efficient energy transfer along the energy chain. In this paper, several methods to improve the efficiency of the energy chain are described. This includes an analysis of optimization methods for photovoltaic powered products, its functional system and product use.Industrial Design Engineerin