974 research outputs found
The Material Culture of Childhood: Problems and Potential in Historical Explanation
The discovery of childhood over the past two centuries, initially by educators, clergy, merchandisers, and sociologists throughout the nineteenth century, and then by childpsychologists, antique dealers, writers, and social historians in the twentieth century, has meant an ever-expanding interest in the role of children and the concept of childhood. Part of this interest has focused on the things of children, on the surviving artifacts of past infancy, childhood and adolescence.
Two questions are posed about this interest in extant childhood artifacts: How and why has the material culture of childhood intrigued so many collectors, curators and scholars? What are the problems and possibilities of using such physical evidence in historical explanation? These questions are explored by reviewing how the objects of the child have been collected, exhibited, and interpreted over the past century. The essay's argument and supporting data, while largely drawn from the American historical experience, aims at providing a tentative overview of the topic.
Résumé
La découverte de la condition de l'enfance au cours des deux derniers siècles, faite d'abord par les éducateurs, les membres du clergé, les spécialistes des techniques marchandes et les sociologues pendant tout le XIXe siècle, puis par les psychologues, les antiquaires, les écrivains et les historiens sociaux, au cours du XXe siècle, a suscité un intérêt sans cesse croissant envers le rôle de l'enfant et le concept de l'enfance. On s'est notamment intéressé aux choses que possédaient les enfants: aux objets des bambins, des enfants et des adolescents d'autrefois, parvenus jusqu'à nous.
Cette étude pose deux questions sur l'intérêt manifesté à propos des objets façonnés ayant appartenu aux enfants et qui ont été conservés. On se demande comment et pourquoi la culture matérielle de l'enfance a suscité la curiosité de tant de collectionneurs, de conservateurs et de spécialistes, et on s'interroge aussi sur la nature des problèmes et des possibilités qu'entraîne l'utilisation de ces témoins d'un autre âge pour expliquer le passé. On explore ces questions en étudiant comment les objets que possédaient les enfants d'autrefois ont été collectionnés, exposés et interprétés depuis un siècle. L'étude, dont les raisonnements et les preuves apportées à l'appui sont tirés en majeure partie de l'histoire américaine, vise à donner provisoirement une vue d'ensemble du sujet
Tests of a Novel Design of Resistive Plate Chambers
A novel design of Resistive Plate Chambers (RPCs), using only a single
resistive plate, is being proposed. Based on this design, two large size
prototype chambers were constructed and were tested with cosmic rays and in
particle beams. The tests confirmed the viability of this new approach. In
addition to showing an improved single-particle response compared to the
traditional 2-plate design, the novel chambers also prove to be suitable for
calorimetric applications
Large quantum dots with small oscillator strength
We have measured the oscillator strength and quantum efficiency of excitons
confined in large InGaAs quantum dots by recording the spontaneous emission
decay rate while systematically varying the distance between the quantum dots
and a semiconductor-air interface. The size of the quantum dots is measured by
in-plane transmission electron microscopy and we find average in-plane
diameters of 40 nm. We have calculated the oscillator strength of excitons of
that size and predict a very large oscillator strength due to Coulomb effects.
This is in stark contrast to the measured oscillator strength, which turns out
to be much below the upper limit imposed by the strong confinement model. We
attribute these findings to exciton localization in local potential minima
arising from alloy intermixing inside the quantum dots.Comment: 4 pages, 3 figures, submitte
TTCPR: a PMC receiver for TTC
Abstract The TTCPR receiver is a mezzanine card intended for use in distributing TTC information to Data Acquisition and Trigger Crates in the ATLAS Prototype Integration activities. An original prototype run of these ~cards was built for testbeam and integration studies, implemented in both the PMC and PCI form factors, using the TTCrx chips from the previous manufacture. When the new TTCrx chips became available, the TTCPR was redesigned to take advantage of the availability and enhanced features of the new TTCRX(1), and a run of 20 PMC cards was manufactured, and has since been used in integration studies and the testbeam. The TTCPR uses the AMCC 5933(2) to manage the PCI port, an Altera 10K30A(3) to provide all the logic so that the functionality may be easily altered, and provides a 4K deep FIFO to retain TTC data for subsequent DMA through the PCI port. In addition to DMA's which are mastered by the Add On logic, communication through PCI is accomplished via mailboxes, interrupts, and the pass-through feature of the 5933. An interface to the I2C bus of the TTCRX is provided so that internal registers may be accessed, and the card supports reinitialization of the TTCRX from PCI. Software has been developed to support operation of the TTCPR under both LynxOS and Linux. I. History of the TTCPR The TTCPR was developed in response to a need for TTC(4) information in the Data Acquisition from TileCal Modules in the ATLAS Test Beam. Specifically, it was desired to have EventID, Bunch Counter, and Trigger Type available from TTC in the data records. It was useful to have the TTC information available to processors in the Data Acquisition crates through PCI ports, and to have the data transferred to the processor's address space via an externally mastered DMA. Accordingly, the TTCPR was designed as a mezzanine card in the PMC form factor. The original cards utilized the older nonradhard version of the TTCRX, because the new radhard version was not available at that time. When it became clear that the new TTCRX would be available soon and also that it would not be possible to obtain any more of the older TTCRX chips, the TTCPR was redesigned, and enhancements were added to take advantage of the features of the new TTCRX. This new TTCPR was produced and has been used successfully in data acquisition at the ATLAS Test Beam. The card has also been implemented in the PCI form factor. The TTCPR in the PMC version is shown in II. Architecture of the TTCPR A block diagram of the TTCPR is shown i
Construction of the Soudan 2 detector
Progress in the construction of the Soudan 2 nucleon decay detector which is being built at the Soudan iron mine in Minnesota is discussed. The expected event rate and characteristics of low energy neutrino events, muon events, multiple muon events, and other cosmic ray phenomena are discussed
A Prototype ROI Builder for the Second Level Trigger of ATLAS Implemented in FPGAs
The design and implementation of a Region of Interest (ROI) Builder connecting the ATLAS Level 1 Trigger to the Level 2 Trigger Supervisor is described. A highly parallel design implemented in high large, high-speed FPGA's is described and results of tests are presented
A mobile data acquisition system
A mobile data aquisition (MobiDAQ) was developed for the ATLAS central hadronic
calorimeter (TileCal). MobiDAQ has been designed in order to test the functionalities of the TileCal
front-end electronics and to acquire calibration data before the final back-end electronics were built
and tested. MobiDAQ was also used to record the first cosmic ray events acquired by an ATLAS
subdetector in the underground experimental area
ATLAS TDAQ RoI Builder and the Level 2 Supervisor system
The ATLAS High Level Trigger (HLT) uses information from the hardware based Level 1 Trigger system to guide the retrieval of information from the readout system. The Level 1 Trigger elements (jet, electromagnetic, muon candidate, etc.) determine Regions of Interest (RoIs) that seed further trigger decisions. This paper describes the device - the RoI Builder (RoIB) - that collects these data from the Level 1 Trigger and the Level 2 Supervisors (L2SV) Farm that makes these data available to the HLT. The status of the system design and the results of the tests and integration into ATLAS TDAQ system are presented
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