Determination of the charge state distribution of a highly ionized coronal Au plasma

We present the first definitive measurement of the charge state distribution of a highly ionized gold plasma in coronal equilibrium. The experiment utilized the Livermore electron beam ion trap EBIT-II in a novel configuration to create a plasma with a Maxwellian temperature of 2.5 keV. The charge balance in the plasma was inferred from spectral line emission measurements which accounted for charge exchange effects. The measured average ionization state was 46.8+/-0.75. This differs from the predictions of two modeling codes by up to four charge states.     

A single-chip Si-bipolar 1.6-GHz VCO with integrated-bias network

A single-chip 2.7-V voltage-controlled oscillator (VCO) with an integrated-bias network has been implemented in an Si-bipolar process with an f_T of 25 GHz. With an on-chip resonator consisting of vertically coupled inductors and varactor diodes, an oscillation frequency of 1.56 GHz was measured. A careful design of the oscillator and bias network was necessary to achieve a phase noise performance of -139 dBc/Hz at 4.7 h MHz off carrier. The tuning sensitivity was 100 MHz/V, which is sufficient to compensate for production tolerances. The VCO can be used as a building block for single-chip transceivers in digital European cordless telephone or global system for mobile communication systems     

An Adaptive Digital Front-End for Multimode Wireless Receivers

The ongoing evolution from 2G to 3G and beyond requires multimode operation of wireless cellular transceivers. This paper discusses the design of an adaptive wireless receiver for multimode operation and power efficiency. This is achieved by sharing digital signal processing stages for all operation modes and adapting them such that performance requirements are met at a minimum power consumption. The flexibility a digital front-end introduces in combination with an analog zero-intermediate-frequency receiver is studied with respect to the main cellular communication standards (Global System for Mobile Communication, Enhanced Data Rates for Global Evolution, Wide-Band Code-Division Multiple Access (WCDMA)/High-Speed Downlink Packet Access, and CDMA2000 and satellite navigation systems (Galileo), with considerations of impacts on the capability of an implementation of a software-defined radio. The proposed approach is verified by simulations exhibiting an error-vector magnitude of 2.9% in Universal Mobile Telecommunications System mode while the estimated power consumption can be reduced by 62% versus full featured mode at reasonable degradation in modulation quality.     

Towards Washout Filter Concepts for Motion Simulators on the Base of a Stewart Platform

In this paper we present a pneumatically driven Stewart platform as a basis for motion simulators. Motion platforms, that simulate perceived situations in aeroplanes, cars or ships, have workspace constraints in every degree of freedom. Therefore it is necessary to adapt the accelerations and angular rates in order to stay within the physical restrictions. For realizing a flight or ride simulator on the basis of the Stewart platform, “ Washout Filters” are used to change the signals of the open source software FlightGearand to minimize the sensation error between simulator and aircraft. Different filter concepts are implemented and evaluated. The platform presented in this document is a parallel kinematic robot, driven by fluidic muscles. The pneumatically actuated muscles are only able to produce tensile forces. Therefore a spiral spring from a passenger car is used to apply the compressive forces and torques. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A novel ethylene-bridged spiro[3.2]Hexane

3,3-Dichlorotricyclo[5.1.0.0^1,4]oct-5-en-2-one ($\text{1}$) was prepared by addition of dichloroketene to 1,3-cyclohexadiene followed by allylic bromination and dehydrobromination.     

Fast switching ferroelectric liquid-crystalline polymers

Ferroelectric liquid-crystalline side chain polymers containing polyacrylate or polysiloxane main chains, a mesogenic unit of three aromatic cores and chiral end groups were synthesized and characterized by D.S.C., optical microscopy, and X-ray diffraction. Polyacrylates with a flexible spacer of eleven methylene groups exhibit fast bistable switching in oriented samples (2 to 4μm cells) with response times of some ms at low D.C. voltages, making these polymers interesting for the fabrication of electrooptical devices. Somewhat longer response times were found for the first switchable polysiloxanes. In this case some problems in obtaining well orientated samples have to be solved.     

Analytik bakterientoxischer Effekte mit Hilfe genetisch konstruierter Leuchtbakterien

Zusammenfassung Leuchtbakterienteste stellen eine elegante Methode zur schnellen, reproduzierbaren Bestimmung bakterientoxischer Effekte dar. Einer allgemeinen Anwendung steht allerdings entgegen, daß die Luminescenzeigenschaften auf relativ wenige Bakterienfamilien mit zum Teil extremen Standortansprüchen beschränkt sind. Die Übertragbarkeit der Meßergebnisse auf interessierende Anwendungen ist deshalb in vielen Fällen nicht gegeben. In der vorliegenden Arbeit wird am Beispiel eines gentechnologisch konstruierten luminescenten Abwasserstammes gezeigt, daß durch Verwendung von anwendungsspezifischen Testorganismen das Anwendungsspektrum von Leuchtbakterientesten erweitert werden kann.

---

Analysis of microbial toxicity using gentechnologically constructed luminescent bacteria

Summary Luminescent bacteria bioassays represent an elegant method for fast and reproducible determination of microbial toxicity. A general application of this method is however prevented by the fact that the capability for bioluminescence is restricted to a relatively small group of bacteria with extreme environmental demands. Therefore it seems questionable whether results obtained with those organisms can be used for all interesting applications. It is shown in this paper, that the field of applications for bacterial luminescent assays can be widened using gentechnologically constructed luminescent bacteria.

---

---

Herrn Prof. Dr. H. Hartkamp zum 60. Geburtstag gewidmet     

Synthesis and acylation of 2-nitro-11H-dibenzo[b,e][1,4]dioxepin

A one-pot synthesis of the 11H-dibenzo[b,e]1,4]dioxepin ring system from catechol and an o-chlorobenzyl chloride is described. Friedel-Crafts acylation occurs at the 7-position as shown by X-ray analysis.