Chemical aspects related to using recycled geopolymers as aggregates

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Despite extensive research into sustainability of geopolymers, end-of-life aspects have been largely overlooked. A recycling scenario is examined in this study. This requires an investigation of alkali leaching potential from a geopolymeric matrix. To study the feasibility of geopolymer cement (GPC) recycling, the migration of alkalis was evaluated for the first time on a microstructural level through energy dispersive X-ray (EDX) scanning electron microscopy (SEM) elemental mapping and leaching tests. Macroscale impacts were assessed through an investigation of Portland cement (PC) mortar properties affected by alkali concentration. Leaching tests indicated that alkalis immediately become available in aqueous environments, but the majority remain chemically or physically bound in the matrix. This type of leaching accelerates the initial setting of PC paste. Elemental mapping and EDX/SEM analysis showed a complex paste-aggregate interfacial transition zone. Exchange of calcium and sodium, revealed by the maps, resulted in the migration of sodium into the PC paste and the formation of additional calcium-silicon-based phases in the geopolymeric matrix. Strength values of mortars with 25% and 50% recycled aggregates (RA) showed negligible differences compared with the reference sample. Screening tests indicated a low potential for GPC RA inducing alkali-silica reaction. Transport of GPC RA alkalis and the underlying mechanisms were observed. This transport phenomenon was found to have minor effects on the properties of the PC mortar, indicating that recycling of geopolymers is a viable reuse practice.Peer reviewedFinal Published versio

Accent attribution in speakers with Foreign Accent Syndrome

Purpose: The main aim of this experiment was to establish the extent to which the impression of foreignness in speakers with Foreign Accent Syndrome (FAS) is in any way comparable to the impression of foreignness in speakers with a real foreign accent. Method: Three groups of listeners attributed accents to conversational speech samples of 5 FAS speakers which were embedded amongst those of 5 speakers with a real foreign accent and 5 native speaker controls. The listener groups differed in their familiarity with foreign accented speech and speech pathology. Results: The findings indicate that listeners’ perceptual reactions to the three groups of speakers are essentially different at all levels of analysis. The native speaker controls are unequivocally considered as native speakers of Dutch while the speakers with a real foreign accent are very reliably assessed as non-native speakers. The speakers with Foreign Accent Syndrome, however, are in some sense perceived as foreign and in some sense as native by listeners, but not as foreign as speakers with a real foreign accent nor as native as real native speakers. This result may be accounted for in terms of the trigger support model of foreign accent perception. Conclusions: The findings of the experiment is consistent with the idea that the very nature of the foreign accent in different in both groups of speakers, although it cannot be fully excluded that the perceived foreignness in the two groups is one of degree

'Policing' in Europese Metropolen

In dit nummer van de Orde van de Dag worden de allereerste resultaten gepresenteerd van het internationaal onderzoeksproject ‘Policing European Metropolises’, een comparatief project in grote wereldsteden, dat door Prof. Em. P. Ponsaers en Dr. E. Devroe werd opgezet in april 2013. U vindt in dit nummer resultaten voor Londen, Berlijn, Rome, Parijs, Barcelona,Sofia en Amsterdam. We schetsen in deze inleiding het onderzoeksthema, de doelstellingen van dit project, de methode en het procesmatige verloop. In tweede instantie lichten we de verschillende bijdragen kort toe.The politics and administration of institutional chang

'Policing' in Europese Metropolen

In dit nummer van de Orde van de Dag worden de allereerste resultaten gepresenteerd van het internationaal onderzoeksproject ‘Policing European Metropolises’, een comparatief project in grote wereldsteden, dat door Prof. Em. P. Ponsaers en Dr. E. Devroe werd opgezet in april 2013. U vindt in dit nummer resultaten voor Londen, Berlijn, Rome, Parijs, Barcelona,Sofia en Amsterdam. We schetsen in deze inleiding het onderzoeksthema, de doelstellingen van dit project, de methode en het procesmatige verloop. In tweede instantie lichten we de verschillende bijdragen kort toe.The politics and administration of institutional chang

Optimisation of the Monitoring Strategy of Macroinvertebrate Communities in the River Dender, in Relation to the EU Water Framework Directive

The Dender basin in Flanders (Belgium) was used as a case study to implement the European Union (EU) Water Framework Directive. During the last 5 years, ample research on pollution loads and ecological water quality has been done on the Dender River. In addition to biological sampling of macroinvertebrates and fish, automated measurement stations were also used to investigate the spatial-temporal variability of the physical-chemical water quality. This research revealed that the pollution of the Dender River is highly variable. The high nutrient loads result in severe algae blooms during summer, leading to very complex diurnal processes. In this paper, the monitoring strategy for the assessment of the biological water quality in the Dender basin has been reviewed in relation to the EU Water Framework Directive. For this, seasonal macroinvertebrate data were collected and assessed. General trends and hidden structures in these data were analysed by means of classification trees, using different inputs (seasons, river types, and subbasins). Validation of the results was obtained by applying statistical methods. Analysis about the presence and abundance of the macroinvertebrates revealed that there is a distinct difference between the biological water quality in the Dender stem river and its tributaries. There are also seasonal differences between the macroinvertebrate communities when the Dender and its tributaries are examined separately. An optimised monitoring strategy is proposed based on these results and the EU Water Framework Directive. This includes two monitoring campaigns in summer and winter every 3 years. Furthermore, a cyclic monitoring scheme was developed to minimise sampling efforts

Implications of taxonomic modifications and alien species on biological water quality assessment as exemplified by the Belgian Biotic Index method

BRIEF OF APPELLEE THIS IS AN APPEAL FROM THE FINAL JUDGMENT OF THE THIRD JUDICIAL DISTRICT COURT, SALT LAKE COUNTY, STATE OF UTAH AFFIRMING THE ORDER OF SUSPENSION OF THE DRIVER\u27S LICENSE SERVICES, RENDERED IN AN ADMINISTRATIVE ADJUDICATION HEARING, THE HONORABLE RAYMOND S. UNO, JUDGE PRESIDING

Four cycles of BEP versus an alternating regime of PVB and BEP in patients with poor-prognosis metastatic testicular non-seminoma; a randomised study of the EORTC Genitourinary Tract Cancer Cooperative Group.

We have investigated whether an alternating induction chemotherapy regimen of PVB/BEP is superior to BEP in patients with poor-prognosis testicular non-seminoma. A total of 234 eligible patients were randomised to receive an alternating schedule of PVB/BEP for a total of four cycles or four cycles of BEP. Poor prognosis was defined as any of the following: lymph node metastases larger than 5 cm, lung metastases more than four in number or larger than 2 cm, haematogenic spread outside the lungs, such as in liver and bone, human chorionic gonadotrophin > 10,000 IU l-1 or alphafetoprotein > 1000 IU l-1. The complete response (CR) rates to PVB/BEP and BEP were similar, 76% and 72% respectively (P = 0.58). In addition, there was no significant difference in relapse rate, disease-free and overall survival at an average follow-up of 6 years. The 5-year progression-free and survival rates in both treatment groups were approximately 80%. The PVB/BEP regime was more toxic with regard to bone marrow function; the frequencies of leucocytes below 1000 microliters-1, leucocytopenic fever and platelets below 25,000 microliters-1, throughout four cycles were 28% vs 5% (P < 0.001), 16% vs 5% (P = 0.006), and 10% vs 1% (P = 0.001) respectively. Neuropathy also occurred more often in the PVB/BEP arm: 47% vs 25% (P = 0.001). This study shows that an alternating regimen of PVB/BEP is not superior to BEP and that it is more myelo- and neurotoxic