INVESTIGATION OF THE MECHANISMS OF HEAT EXCHANGER CORROSION IN A MUNICIPAL WASTE INCINERATION PLANT BY ANALYSIS OF THE RAW GAS AND VARIATION OF OPERATING PARAMETERS

The detailed mechanism of high temperature chlorine corrosion, the dominant cause of corrosion in a municipal solid waste incinerator (MSI), has still to be clarified (Schroer, 2002). Upon its way through the boiler the raw gas is subject to various physical and chemical processes and interactions. Of these, sulphation of chlorides is supposed to have the major impact on chlorine corrosion (Neumann, 1997). The physical and chemical mechanisms of corrosion were investigated at a municipal solid waste incinerator. Both, the particulate and gas phase of the flue gas, were chemically and physically analyzed during their way through the boiler, at temperatures from close to 1000 °C down to 200 °C. The raw gas composition was analyzed during normal operation and soot blowing cleaning routine. Additionally, operating parameters of the plant were varied, and deposition processes were evaluated with the aim to find out primary measures to reduce corrosion rates. The particle mass concentration exhibits a bimodal size distribution with maxima at approximately 0.5 μm – growing by duration of travel – and 100 μm. First results show that sulphation of the particles can be observed upon travel through the boiler and on the fouling. Sulphur containing additives increased the sulphation of the particles during flight though not to completion

Solvent extraction studies of coprocessing flowsheets: Results from Campaign 6 of the Solvent Extraction Test Facility (SETF)

A series of five solvent extraction tests were made in the Solvent Extraction Test Facility (SETF) during Campaign 6. Each test used a coprocessing flowsheet that included coextraction-coscrubbing of the heavy metals followed by partial partitioning of the uranium and plutonium into separate uranium and uranium-plutonium products. The separation of the uranium and plutonium was aided by the addition of HNO{sub 2} to the organic backscrub stream. Two of these tests compared the performance of the traditional Purex solvent, tri-n-butyl phosphate (TBP), with a potential replacement, tri-2-ethylhexyl phosphate (TEHP). The remaining three tests were made with a chemically-degraded TBP solvent to compare the effectiveness of two solvent cleanup methods - treatment with silica gel or scrubbing with sodium carbonate and water

Solvent extraction studies of coprocessing flowsheets: results from Campaign 5 of the Solvent Extraction Test Facility (SETF)

In Campaign 5, fast breeder reactor (FBR) fuel [average burnup {similar_to}2.6 TJ/kg ({similar_to}30,000 MWd/t)] was processed for the first time. Operations in a single extraction cycle with 30% TBP-NPH were satisfactory with low heavy-metal losses (< 0.02%) and high decontamination factors (DFs > 1000) for all fission products except {sup 95}Zr, which exhibited moderate DFs (180 and 750, respectively, in two runs). The use of a split scrub stream (0.5 M and 3 M HNO{sub 3}) vs a single scrub stream (3 M HNO{sub 3}) resulted in the higher DF. An extractant backscrubbing stream was not needed to produce partially partitioned uranium-plutonium products containing 30 to 35% plutonium when processing the core FBR fuel (22% Pu). The necessary enrichment factor ({similar_to}1.5) was attained by maintaining the temperature at 25 to 30{sup 0}C in partial partitioning and adjusting the relative flow rates of the aqueous and organic phases. The plutonium recovery in the two runs ({similar_to}400 g) was purified by anion exchange and converted to PuO{sub 2} for fuel refabrication studies. 8 references, 7 figures, 6 tables

Solvent extraction studies of coprocessing flowsheets: results from campaigns 3 and 4 of the Solvent-Extraction Test Facility (SETF)

Experiments on tri-n-butyl phosphate solvent extraction of uranium and plutonium at full activity levels (Campaigns 3 and 4) were conducted in the Solvent Extraction Test Facility (SETF), located in one of the heavily shielded cells of the Transuranium Processing Plant. The primary objectives were: (1) to demonstrate and evaluate the first two cycles of the Hot Engineering Facility flowsheets (codecontamination and partial partitioning), and (2) to investigate and evaluate the use of HNO{sub 2} as the reductant for tetravalent plutonium during reductive stripping operations. Secondary objectives were to determine the solvent extraction behavior of feed solutions prepared by dissolving fuel from a boiling water reactor (BWR) and to improve the solvent extraction feed clarification

Disk-Jet Connection in the Radio Galaxy 3C 120

We present the results of extensive multi-frequency monitoring of the radio galaxy 3C 120 between 2002 and 2007 at X-ray, optical, and radio wave bands, as well as imaging with the Very Long Baseline Array (VLBA). Over the 5 yr of observation, significant dips in the X-ray light curve are followed by ejections of bright superluminal knots in the VLBA images. Consistent with this, the X-ray flux and 37 GHz flux are anti-correlated with X-ray leading the radio variations. This implies that, in this radio galaxy, the radiative state of accretion disk plus corona system, where the X-rays are produced, has a direct effect on the events in the jet, where the radio emission originates. The X-ray power spectral density of 3C 120 shows a break, with steeper slope at shorter timescale and the break timescale is commensurate with the mass of the central black hole based on observations of Seyfert galaxies and black hole X-ray binaries. These findings provide support for the paradigm that black hole X-ray binaries and active galactic nuclei are fundamentally similar systems, with characteristic time and size scales linearly proportional to the mass of the central black hole. The X-ray and optical variations are strongly correlated in 3C 120, which implies that the optical emission in this object arises from the same general region as the X-rays, i.e., in the accretion disk-corona system. We numerically model multi-wavelength light curves of 3C 120 from such a system with the optical-UV emission produced in the disk and the X-rays generated by scattering of thermal photons by hot electrons in the corona. From the comparison of the temporal properties of the model light curves to that of the observed variability, we constrain the physical size of the corona and the distances of the emitting regions from the central BH.Comment: Accepted for publication in the Astrophysical Journal. 28 pages, 21 figures, 2 table

L’accompagnement-citoyen en soutien à la participation sociale des aînés ayant un traumatisme craniocérébral

Hautement valorisée par les aînés, la participation sociale a des effets bénéfiques sur leur santé biopsychosociale. Tous n’ont pas cependant les mêmes opportunités pour s’investir dans ce type d’activités; particulièrement ceux ayant un traumatisme craniocérébral (TCC) qui sont plus susceptibles d’être limités dans leurs capacités à participer à la vie de la communauté. Les initiatives les plus courantes pour aider ces personnes consistent en une assistance humaine visant àpallierleurs limitations et ne misent pas, en priorité, sur la promotion de leurs compétences. Afin d’optimiser l’aide reçue, un accompagnementcitoyen personnalisé à l’intégration communautaire (APIC) a été développé, implanté et évalué. Cet article documente l’impact de l’APIC sur la participation sociale d’aînés ayant un TCC. Une analyse de contenu thématique a été réalisée sur les données issues d’entrevues semi-dirigées auprès des participants et des journaux de bord des accompagnateurs. Les résultats montrent trois grandes retombées de l’APIC : une meilleure assurance et un plus grand sentiment d’autonomie, un goût retrouvé de s’investir dans des activités de loisirs signifiantes, et une plus grande ouverture vers de nouvelles possibilités de relations.Abstract : Highly valued by seniors, community integration has beneficial effects on their biopsychosocial health. However, not all of them have the same opportunities to engage in social participation activities, particularly those with traumatic brain injury (TBI) who are more likely to be limited in their abilities to participate in the life of the community. The most common initiatives to help these people consist of human assistance to overcome their limitations and which do not focus on skills promotion. In order to optimize the available services and resources, personalized citizen assistance for community integration (APIC) has been developed, implemented, and evaluated. This article documents the impact of APIC on the community integration of seniors with TBI. A thematic content analysis was conducted on data from semi-structured interviews with participants and from attendant logbooks. The results show three major spin-offs from APIC: better insurance and a greater sense of autonomy, a renewed taste for investing in meaningful leisure activities, and greater openness to new relationship opportunities

Multidimensional signals and analytic flexibility: Estimating degrees of freedom in human speech analyses

Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis which can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling, but also from decisions regarding the quantification of the measured behavior. In the present study, we gave the same speech production data set to 46 teams of researchers and asked them to answer the same research question, resulting insubstantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further find little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system and calibrate their (un)certainty in their conclusions