Compaction of tool steels by pulsed electric current (PECS) sintering process

This study had two major purposes: the microstructural investigation of High Chromium White Iron (HCWI) sintered with Pulsed Electric Current Sintering (PECS) and the evaluation of the abrasion resistance of high chromium white iron mixed with different amounts of Hadfield Steel. The objective was to obtain dense high chromium white iron compacts with fine and uniform carbide and grain structure. The materials included in the study were gas atomized high chromium white iron (2.60 wt% C, 19.48 wt% Cr, 1.02 wt% Nb) and Hadfield steel (1.95 wt% C, 4.09 wt% Cr, 13.87 wt% Mn).The experimental procedure involved preparation and characterization of the starting powders, consolidation of the powders by pulsed electric current sintering process, and characterization of the resulting compacts. Microstructural studies were carried out to establish a relationship between processing conditions and the resulting microstructure. Abrasion testing was conducted (dry sand rubber wheel test) to investigate the effect of Hadfield additions to the wear performance of the material.The optimal sintering parameters for obtaining dense high chromium white iron included sintering the material at 1050 °C for 5 minutes, heating rate being 100 °C/min and compaction pressure 50 MPa. The resulting microstructure contained fine chromium carbides dispersed in a martensitic steel matrix. The modification of dwell time and the heating rate did not influence the microstructure to any significant degree. In the abrasion tests the high chromium white iron performed noticeably better (~20% lower weight loss) than the material mixed with Hadfield steel in the abrasion test. The performance of the Hadfield steel was only slightly worse (~7% higher wear loss) than that of the high chromium white iron

Bianchi Cosmologies: New Variables and a Hidden Supersymmetry

We find a supersymmetrization of the Bianchi IX cosmology in terms of Ashtekar's new variables. This provides a framework for connecting the recent results of Graham and those of Ryan and Moncrief for quantum states of this model. These states are also related with the states obtained particularizing supergravity for a minisuperspace. Implications for the general theory are also briefly discussed.Comment: 15 Pages, RevTex, NSF-ITP-93-9

The Optimized Model of Multiple Invasion Percolation

We study the optimized version of the multiple invasion percolation model. Some topological aspects as the behavior of the acceptance profile, coordination number and vertex type abundance were investigated and compared to those of the ordinary invasion. Our results indicate that the clusters show a very high degree of connectivity, spoiling the usual nodes-links-blobs geometrical picture.Comment: LaTeX file, 6 pages, 2 ps figure

Miguel Littín e a imaginação da história

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Filosofia e Ciências Humanas. História.Este ensaio perpassa diferentes questões a respeito das possibilidades do pensamento histórico no que diz respeito às suas condições e intensões de imaginar uma comunidade sobrevivente. O personagem utilizado em tal empresa é o cineasta chileno Miguel Littín, sujeito que apresenta imagens emblemáticas para pensar a relação entre a vontade de agir na comunidade e as razões temporais que mobilizam essas vontades, que serão prismadas à partir de escritos de Jacques Rancière e Georges Didi-Huberman

Receipt from Postal Telegraph-Cable Company to Estate Robt Goelet

https://digitalcommons.salve.edu/goelet-new-york/1068/thumbnail.jp

Destination memory in Alzheimer's Disease: when I imagine telling Ronald Reagan about Paris

Destination memory refers to remembering the destination of information that people output. This present paper establishes a new distinction between external and internal processes within this memory system for both normal aging and Alzheimer\u27s Disease (AD). Young adults, older adults, and mild AD patients were asked either to tell facts (i.e., external destination memory condition) or to imagine telling facts (i.e., internal destination memory condition) to pictures of famous people. The experiment established three major findings. First, the destination memory performance of the AD patients was significantly poorer than that of older adults, which in turn was poorer than that of the young adults. Furthermore, internal destination processes were more prone to being forgotten than external destination memory processes. In other words, participants had more difficulty in remembering whether they had previously imagined telling the facts to the pictures or not (i.e., imagined condition) than in remembering whether they had previously told the facts to the pictures or not (i.e., enacted condition). Second, significant correlations were detected between performances on destination memory and several executive measures such as the Stroop, the Plus-Minus and the Binding tasks. Third, among the executive measures, regression analyses showed that performance on the Stroop task was a main factor in explaining variance in destination memory performance. Our findings reflect the difficulty in remembering the destination of internally generated information. They also demonstrate the involvement of inhibitory processes in destination memory

Tone-activated, remote, alert communication system

Pocket sized transmitter, frequency modulated by crystal derived tones, with integral loop antenna provides police with easy operating alert signal communicator which uses patrol car radio to relay signal. Communication channels are time shared by several patrol units

Total Hip Joint Replacement Biotelemetry System

The development of a biotelemetry system that is hermetically sealed within a total hip replacement implant is reported. The telemetry system transmits six channels of stress data to reconstruct the major forces acting on the neck of the prosthesis and uses an induction power coupling technique to eliminate the need for internal batteries. The activities associated with the telemetry microminiaturization, data recovery console, hardware fabrications, power induction systems, electrical and mechanical testing and hermetic sealing test results are discussed