16 research outputs found
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A transuranic aerosol measurement system: Preliminary results
We have completed the design, fabrication, and assembly of a computer-based prototype system for the measurement of transuranic aerosols in the workplace and environment. This system (called WOTAMS for Workplace Transuranic Aerosol Measurement System) incorporates two detectors: (1) an in-line solid-state alpha detector that sends out an alarm the moment a transuranic release occurs, and (2) an in-vacuum detector that increases off-line-analysis sensitivity. The in-line sensitivity of the system is better than 5.0 MPC-h, and the in-vacuum sensitivity exceeds 0.5 MPC-h. 5 refs., 8 figs., 1 tab
Effects of natural weathering on microstructure and mineral composition of cementitious roofing tiles reinforced with fique fibre
The objective of the present work was to evaluate the effects of 14 years of weathering exposition on the microstructure and mineral composition of cementitious roofing tiles, still in service, reinforced with fique fibres (Furcrae gender). The results show that tiles under weathering exposition presented higher water absorption and apparent void volume than tiles under laboratory exposition. The continuous hydration of cement and natural carbonation filled the smaller pores but contrarily the large pores remained in the porous fibre to matrix interface in the samples exposed to weathering. On the other hand, their microstructure presented lower air permeability than samples aged in the internal environment of the laboratory. Besides, in the weathering aged tiles takes place a more intensive hydration process as it was identified greater amount of hydrated phases than in the laboratory aged specimens. The present results contribute to understanding the consequences of tropical weathering on the fibre-cement degradation. (C) 2010 Elsevier Ltd. All rights reserved.CNPqCapesFapesp, BrazilColcienciasMinistery of Agriculture and Rural Development, Colombi
P1530: PERITRANFUSIONAL C1-INHIBITOR IN PATIENTS WITH SEVERE COMPLEMENT-MEDIATED AUTOIMMUNE HEMOLYTIC ANEMIA: AN OPEN LABEL PHASE 2 TRIAL.
C1-inhibitor treatment in patients with severe complement-mediated autoimmune hemolytic anemia.
Culturable bacteria community development in postglacial soils of Ecology Glacier, King George Island, Antarctica
Glacier forelands are excellent sites in which to study microbial succession because conditions change
rapidly in the emerging soil. Development of the bacterial community was studied along two transects on lateral
moraines of Ecology Glacier, King George Island, by culture-dependent and culture-independent approaches
(denaturating gradient gel electrophoresis, DGGE). Environmental conditions such as cryoturbation and soil
composition affected both abundance and phylogenetic diversity of bacterial communities. Microbiocenosis
structure along transect 1(severe cryoturbation) differed markedly from that along transect 2 (minor
cryoturbation). Soil physical and chemical factors changed along the chronosequence (time since exposure) and
influenced the taxonomic diversity of cultivated bacteria (CB), particularly along transect 2. Arthrobacter spp.
played a pioneer role, and were present in all soil samples, but were most abundant along transect 1. Cultivated
bacteria isolated from transect 2 were taxonomically more diverse than those cultivated from transect 1; those
from transect 1 tended to express a broader range of enzyme and assimilation activities. Our data suggest that
cryoturbation is a major factor in controlling bacterial community development in postglacial soils, shed light on
microbial succession in glacier forelands, and add a new parameter to models that describe succession
phenomena
Production of Low-Phosphorus Molten Iron from High-Phosphorus Oolitic Hematite Using Biomass Char
Getting rid of the unwanted: highlights of developments and challenges of biobeneficiation of iron ore mineralsâa review
Thermal Analysis of the Formation of Chunky Graphite during Solidification of Heavy-section Spheroidal Graphite Iron Parts
Analysis of cooling curves recorded at the centre of large blocks cast with near-eutectic spheroidal graphite cast irons prone to give chunky graphite has been checked against microstructure observations. It has been observed that solidification proceeds totally at temperatures lower than the stable eutectic temperature and the following solidification sequence could be proposed: 1) nucleation of primary graphite in the liquid; 2) initial eutectic reaction processing by growth of austenite-like dendrites encapsulating the primary nodules; 3) bulk eutectic reaction related to nucleation and then growth of CHG cells and of secondary nodules, these latter giving spheroidal graphite eutectic cells. It was found that the maximum recalescence during the eutectic reaction first increases with the volume of the block affected by chunky graphite, and then decreases when most of the material is affected. Interestingly enough, a relationship between the volume of the blocks affected by CHG and the recalescence measured on TA cups has been observed