The Outer Tracker Detector of the HERA-B Experiment. Part II: Front-End Electronics

The HERA-B Outer Tracker is a large detector with 112674 drift chamber channels. It is exposed to a particle flux of up to 2x10^5/cm^2/s thus coping with conditions similar to those expected for the LHC experiments. The front-end readout system, based on the ASD-8 chip and a customized TDC chip, is designed to fulfil the requirements on low noise, high sensitivity, rate tolerance, and high integration density. The TDC system is based on an ASIC which digitizes the time in bins of about 0.5 ns within a total of 256 bins. The chip also comprises a pipeline to store data from 128 events which is required for a deadtime-free trigger and data acquisition system. We report on the development, installation, and commissioning of the front-end electronics, including the grounding and noise suppression schemes, and discuss its performance in the HERA-B experiment

Electromagnetic containerless processing requirements and recommended facility concept and capabilities for space lab

Containerless melting, reaction, and solidification experiments and processes which potentially can lead to new understanding of material science and production of new or improved materials in the weightless space environment are reviewed in terms of planning for spacelab. Most of the experiments and processes discussed are amenable to the employment of electromagnetic position control and electromagnetic induction or electron beam heating and melting. The spectrum of relevant properties of materials, which determine requirements for a space laboratory electromagnetic containerless processing facility are reviewed. Appropriate distributions and associated coil structures are analyzed and compared on the basis of efficiency, for providing the functions of position sensing, control, and induction heating. Several coil systems are found capable of providing these functions. Exchangeable modular coils in appropriate sizes are recommended to achieve the maximum power efficiencies, for a wide range of specimen sizes and resistivities, in order to conserve total facility power

Practical small-scale explosive seam welding

A small-scale explosive seam welding process has been developed that can significantly contribute to remote metal joining operations under hazardous or inaccessible conditions, such as nuclear reactor repair and assembly of structure in space. This paper describes this explosive seam welding process in terms of joining principles, variables, types of joints created, capabilities, and applications. Very small quantities of explosive in a ribbon configuration are used to create narrow (less than 0.5 inch), long-length, uniform, hermetically sealed joints that exhibit parent metal properties in a wide variety of metals, alloys, and combinations. The practicality of this process has been demonstrated by its current acceptance, as well as its capabilities that are superior in many applications to the universally accepted joining processes, such as mechanical fasteners, fusion and resistance welding, and adhesives

Developing vanadium redox flow technology on a 9-kW 26-kWh industrial scale test facility: Design review and early experiments

Redox Flow Batteries (RFBs) have a strong potential for future stationary storage, in view of the rapid expansion of renewable energy sources and smart grids. Their development and future success largely depend on the research on new materials, namely electrolytic solutions, membranes and electrodes, which is typically conduced on small single cells. A vast literature on these topics already exists. However, also the technological development plays a fundamental role in view of the successful application of RFBs in large plants. Despite that, very little research is reported in literature on the technology of large RFB systems. This paper presents the design, construction and early operation of a vanadium redox flow battery test facility of industrial size, dubbed IS-VRFB, where such technologies are developed and tested. In early experiments a peak power of 8.9 kW has been achieved with a stack specific power of 77Wkg−1. The maximum tested current density of 635 mA cm−2 has been reached with a cell voltage of 0.5 V, indicating that higher values can be obtained. The test facility is ready to be complemented with advanced diagnostic devices, including multichannel electrochemical impedance spectroscopy for studying aging and discrepancies in the cell behaviors

Technology and benefits of aircraft counter rotation propellers

Results are reported of a NASA sponsored analytical investigation into the merits of advanced counter rotation propellers for Mach 0.80 commercial transport application. Propeller and gearbox performance, acoustics, vibration characteristics, weight, cost and maintenance requirements for a variety of design parameters and special features were considered. Fuel savings in the neighborhood of 8 percent relative to single rotation configurations are feasible through swirl recovery and lighter gearboxes. This is the net gain which includes a 5 percent acoustic treatment weight penalty to offset the broader frequency spectrum noise produced by counter rotation blading

Lecture Script: "EMI Risk Management"

Content of the lecture: Fundamentals and methods of risk analysis; Basic design and technology of IEMI sources (e.g., VIRCATOR, Magnetron, Klystron, …); Modelling of IEMI threat scenarios; EMI effects on electric systems; Protective measure; Discussion and assessment of the risk for critical infrastructures; Case studies on a generic infrastructur

Configuring the Networked Citizen

Among legal scholars of technology, it has become commonplace to acknowledge that the design of networked information technologies has regulatory effects. For the most part, that discussion has been structured by the taxonomy developed by Lawrence Lessig, which classifies code as one of four principal regulatory modalities, alongside law, markets, and norms. As a result of that framing, questions about the applicability of constitutional protections to technical decisions have taken center stage in legal and policy debates. Some scholars have pondered whether digital architectures unacceptably constrain fundamental liberties, and what public design obligations might follow from such a conclusion. Others have argued that code belongs firmly on the private side of the public/private divide because it originates in the innovative activity of private actors. In a forthcoming book, the author argues that the project of situating code within one or another part of the familiar constitutional landscape too often distracts legal scholars from more important questions about the quality of the regulation that networked digital architectures produce. The gradual, inexorable embedding of networked information technologies has the potential to alter, in largely invisible ways, the interrelated processes of subject formation and culture formation. Within legal scholarship, the prevailing conceptions of subjectivity tend to be highly individualistic, oriented around the activities of speech and voluntary affiliation. Subjectivity also tends to be understood as definitionally independent of culture. Yet subjectivity is importantly collective, formed by the substrate within which individuality emerges. People form their conceptions of the good in part by reading, listening, and watching—by engaging with the products of a common culture—and by interacting with one another. Those activities are socially and culturally mediated, shaped by the preexisting communities into which individuals are born and within which they develop. They are also technically mediated, shaped by the artifacts that individuals encounter in common use. The social and cultural patterns that mediate the activities of self-constitution are being reconfigured by the pervasive adoption of technical protocols and services that manage the activities of content delivery, search, and social interaction. In developed countries, a broad cross-section of the population routinely uses networked information technologies and communications devices in hundreds of mundane, unremarkable ways. We search for information, communicate with each other, and gain access to networked resources and services. For the most part, as long as our devices and technologies work as expected, we give little thought to how they work; those questions are understood to be technical questions. Such questions are better characterized as sociotechnical. As networked digital architectures increasingly mediate the ordinary processes of everyday life, they catalyze gradual yet fundamental social and cultural change. This chapter—originally published in Imagining New Legalities: Privacy and Its Possibilities in the 21st Century, edited by Austin Sarat, Lawrence Douglas, and Martha Merrill Umphrey (2012)—considers two interrelated questions that flow from understanding sociotechnical change as (re)configuring networked subjects. First, it revisits the way that legal and policy debates locate networked information technologies with respect to the public/private divide. The design of networked information technologies and communications devices is conventionally treated as a private matter; indeed, that designation has been the principal stumbling block encountered by constitutional theorists of technology. The classification of code as presumptively private has effects that reach beyond debates about the scope of constitutional guarantees, shaping views about the extent to which regulation of technical design decisions is normatively desirable. This chapter reexamines that discursive process, using lenses supplied by literatures on third-party liability and governance. Second, this chapter considers the relationship between sociotechnical change and understandings of citizenship. The ways that people think, form beliefs, and interact with one another are centrally relevant to the sorts of citizens that they become. The gradual embedding of networked information technologies into the practice of everyday life therefore has important implications for both the meaning and the practice of citizenship in the emerging networked information society. If design decisions are neither merely technical nor presumptively private, then they should be subject to more careful scrutiny with regard to the kind of citizen they produce. In particular, policy-makers cannot avoid engaging with the particular values that are encoded