Microwave hybrid fast sintering of red clay ceramics

This work aimed to examine the performance of the hybrid sintering of clay ceramic in a microwave furnace, compared to the sintering process in a conventional furnace. The raw materials were subjected to X-ray fluorescence, loss on ignition (LOI), X-ray diffraction, particle size distribution, real specific mass, and thermogravimetric analyses. The red clay ceramic mass was prepared, extruded, pre-sintered in a conventional furnace at 600°C/60 min, and sintered at temperatures between 700 °C and 1100 °C. The sintering conventional (resistive oven) was carried out for 60 min with a heating rate of 10°C/min. In the microwave furnace, the sintering times were 5, 10, and 15 min, with a heating rate of 50°C/min, with a sintering chamber coated with silicon carbide (susceptor). The sintered specimens were characterized according to linear shrinkage, water absorption, apparent porosity, apparent specific mass, X-ray diffraction, Raman spectroscopy analysis, spectroscopy analysis in the ultraviolet and visible regions, microhardness, and scanning electron microscopy. The results showed that microwave sintering promoted an increase in the microhardness and apparent specific mass, and reduction in water absorption and apparent porosity values, due to greater densification in the microstructure. The best results occurred for specimens sintered at 1100°C.     

Intralesional radiolabeled human monoclonal IgM in human tumor xenografts

Sensory-perceptual abnormalities in people with autism are discussed from two perspectives: published firsthand accounts and existing psychological research evidence. A range of abnormalities, including hyper- and hyposensitivity, sensory distortion and overload, and multichannel receptivity and processing difficulties, are described in firsthand accounts and frequently portrayed as central to the autistic experience. A number of dangers are inherent in uncritically accepting these accounts at face value and in any wider generalization to the autistic population as a whole. Evidence from clinical studies suggests that unusual sensory responses are present in a majority of autistic children, that they are manifested very early in development, and that they may be linked with other aspects of autistic behavior. In addition, experimental studies using a range of indices have found evidence of unusual responses to sensory stimuli in autistic subjects. However the clinical and experimental research to date suffers from serious methodological limitations and more systematic investigation is warranted. Key issues for future psychological research in the area are identified.     

Maturation ponds, rock filters and reedbeds in the UK: statistical analysis of winter performance.

Wastewater treatment technologies suitable for serving large populations are generally reliable and reasonably cost-effective, yet they are almost always financially inappropriate for small communities (< 2,000 p.e.). Comparative cost data suggests that waste stabilization ponds should be an attractive option for small communities, yet perceptions relating to land costs, climate and effluent quality have limited their application in the UK. This paper details typical UK land costs, climate and winter performance data for a pilot-scale waste stabilization pond with various upgrading technologies: system A, two tertiary maturation ponds in series; B, two tertiary maturation ponds in series followed by a reed bed channel; C, a control rock filter; D, an aerated rock filter; and E, a constructed wetland. System D was found to perform best, closely followed by system B.     

Differentiating anxiety and depression in older adults with generalized anxiety disorder.

To examine affect and cognition in differentiating anxiety and depression, 83 older participants with generalized anxiety disorder completed the Cognitive Checklist (CCL) and the Positive and Negative Affect Schedule (PANAS). A 3-factor solution was found for the PANAS: positive affect (PA), anxiety and anger (Negative Affect 1 [NA-1]), and guilt and shame (Negative Affect 2 [NA-2]). A 2-factor structure was noted for the CCL. Correlations with anxiety and depression measures suggested that the CCL Depression (CCL-D) subscale showed stronger correlations with depression, whereas the CCL Anxiety subscale did not uniquely correlate with anxiety. The NA-1 subscale correlated positively with measures of depression and anxiety, whereas the PA subscale showed negative correlations. Hierarchical regression suggested that the CCL-D subscale was a significant predictor of self-reported depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transmission Electron Microscopy and Electron Energy-Loss Spectroscopy Characterization of Glass Phase in Sol-Gel-Derived Mullite

Sol-gel-derived mullite ceramics were processed by pressureless sintering at 1600°, 1650°, and 1700°C for 4 h. Microstructural and microchemical characterization of the mullite materials was performed using transmission electron microscopy, in conjunction with energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy (EELS). Apart from mullite grain diameter and triplepocket size, no major microstructural changes were observed with increasing sintering temperature. Residual glass was present at triple pockets and along two-grain junctions. Not all grain boundaries revealed the presence of a continuous amorphous intergranular film. Clean interfaces were observed only at boundaries with one grain parallel to the [001] orientation (low-energy configuration). Quantitative EELS analysis of mullite grains and glass pockets revealed only small changes in composition with increasing sintering temperature; i.e., the alumina:silica ratio slightly increased for mullite and glass. The analysis implied that mullite with this relatively high aluminum content would not be stable adjacent to residual glass. However, a stable glass-mullite system has been proposed, because impurity cations were detected within glass pockets, which suggested a slight shift of the subsolidus line (glass-mullite/ mullite) to a higher amount of alumina. Energy-loss nearedge structure studies of the Si- L _2,3 edge revealed a similar near-edge structure for the mullite, residual glass, and quartz. Thus, SiO₄ tetrahedra were thought to be the main building units of the glass contained in sintered mullite.     

Reliability Analysis Applied on Land Subsidence Effects of Groundwater Remediation: Probabilistic vs. Deterministic Approach

The quantification of soil variability is one of the most important aspects in the geo-engineering context. The uncertainty analysis is the main part of the reliability assessment for which a quantitative evaluation was performed in this study. The Reliability Index and the Probability of Failure using the First-Order Reliability Method (FORM) represents both, an effective method which is easy to implement at the same time. This work analyzes possible effects of compaction induced into the aquifer of the Scarlino Plain, caused by the extension of the hydraulic barrier for groundwater remediation. The currently implemented vertical barrier is composed of 12 wells which reach the depth of 10 m. The improvement of the project involves the construction of a further 40 clusters, each consisting of a doublet which intercepts different depths (10 and 18 m). The models of the subsoil stratigraphy and of the groundwater were built using a numerical model. The groundwater flow and the piezometric surface in the current configuration of the barrier were studied and the project configuration was evaluated. Using the Aquitard drainage model, the land subsidence was estimated to calculate the maximum admissible displacement related to exhibited goods, the so called territorial vulnerability. The evaluation analysis was performed using a traditional deterministic approach, followed by a reliability method based on probabilistic models. Finally, the respective results were reported in a soil mapping with overlapping layers.