Synergistic fire-retardancy properties of melamine coated ammonium poly(phosphate) in combination with rod-like mineral filler attapulgite for polymer-modified bitumen roofing membranes

A novel intumescent (carbonization, acid donor and foaming) fire retardant that mimics carbon nanotubes was introduced into bitumen roofing and characterized using cone calorimetry as the main analytical tool. The experimental results indicate that 18% (by mass) attapulgite mineral (ATTP) mixed with base bitumen decreased the peak heat release rate per unit area (pHRRPUA) by 10%. Further, incorporation of melamine coated ammonium polyphosphate (MAPP) decreased the pHRRPUA by 52% and a mixture of these (3:1, ATTP:MAPP) decreased the pHRRPUA by 25% as compared to adding CaCO₃ as a filler. The residual mass loss after the cone test was also improved with up to 3%. The indication of a positive synergistic flame retardant effect of the ATTP-MAPP mixture is supported by thermogravimetric analysis. The addition of this rod-like mineral improved the general fire retardant properties of the base bitumen and increased the viscosity. Therefore, the polymer-modified bitumen with both fire retardant and rheological properties (providing mechanical strength) is a promising novel approach in the design of bitumen roofing membranes.     

WATER CHEMISTRY EFFECTS IN IRON ORE CONCENTRATE AGGLOMERATION FEED

ABSTRACT

In two different iron ore processing plants, it was demonstrated that when magnetite concentrate was filtered to prepare it for use as pelletization feed, the moisture that remained in the filter cake had greatly elevated levels of cations compared to the water removed by the filtration process. In particular, calcium concentrations in the filter cake were 565 times higher than in the filtrate water in Plant 1 and 19.4 times higher than the filtrate water in Plant 2. This effect is due to the adsorption of divalent cations on the magnetite surfaces resulting from electrostatic attraction when the pH of the solution is in the range where magnetite has a negative Zeta potential. Measurements of the Zeta potential as a function of pH for magnetite from Plant 2 determined that its point of zero charge (PZC) occurred at pH 3.0 to 3.5, which was much lower than is commonly reported in the literature and demonstrates that the PZC for magnetite is much more variable than is commonly thought. Plant experiments were carried out using carbon dioxide to reduce the pH of filter slurry so that the PZC could be approached. This was intended to allow adsorbed cations to be released from the magnetite surfaces during filtration. The pH adjustment was demonstrated to improve filtration rates by as much as 23%.     

Influence of sea water solution on mortar containing calcium carbonate

Normal Portland cement mortar discs containing precipitated or ground limestone at dosages of 0, 2.5, 5 and 15% were made at water/cement ratios of 0.42 or 0.60. They were hydrated in lime water or sea water solution for periods up to 1 year. The length and modulus of elasticity changes were monitored periodically. Some mortars containing CaCO₃ exhibited more than three times the expansion of the reference in sea water. The expansions were greater in samples containing fine CaCO₃. The modulus of elasticity was especially low for samples containing precipitated CaCO₃ and exposed to sea water.     

Impacts on Children of a Policy to Promote Employment and Reduce Poverty for Low-Income Parents: New Hope After 5 Years.

The impacts of New Hope, a program to increase parent employment and reduce poverty, were measured 5 years after parents were randomly assigned to program or control groups. New Hope had positive effects on children's school achievement, motivation, and social behavior, primarily for boys, across the age range 6-16. In comparison to impacts measured 2 years after program onset, effects on achievement were robust, but effects on social behavior were reduced. The program produced improvements in family income and use of organized child care and activity settings, suggesting possible pathways by which the New Hope package of policies influenced children's behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Results of radiotherapy of ureteral obstruction in invasive bladder cancer

Retrospective evaluation of the records of 574 patients with muscle-invasive bladder cancer revealed 90 patients (16%) with ureteric obstruction; the obstruction was bilateral in 24%. The effect of radiotherapy was assessed in 55 patients with 68 obstructed kidneys. Six patients with eight obstructed kidneys required percutaneous nephrostomy or ureteric catheters in addition to radiotherapy. Drainage improved in only 20% of kidneys and the diverting catheter could be withdrawn permanently in only one (17%) of the diverted patients. The median survival was 11 months. Irradiation was followed by significant complications in 37 patients (67%). This raises doubts about the assumed beneficial effect of irradiation on ureteric obstruction due to muscle invasive bladder cancer. The short median survival of 11 months confirms that ureteric obstruction is a poor prognostic factor in muscle invasive bladder cancer.     

Concentrations and spatial variations of cyclodienes and other organochlorines in herring and perch from the Baltic Sea

Naive T lymphocytes specific for a given primary antigen occur in low frequencies and require the relevant antigen to be presented by specialist antigen presenting cells (APC), i.e., dendritic cells (DC). For these reasons, the in vitro induction of primary T lymphocyte responses remains a significant technical challenge. We have attempted to improve current strategies for generating in vitro responses by optimising (i) isolation and concomitant activation of DC from peripheral blood, (ii) uptake, processing and presentation of antigen by DC and (iii) antigen driven T lymphocyte proliferation. We established that RPMI 1640 media supplemented with 10% autologous serum resulted in the best yield of CMRF-44+, CD14-, CD19- DC after enrichment over a Nycodenz gradient. Optimal presentation of whole protein and peptide antigen was achieved by addition after the purification of the APC, i.e., at the start of the T lymphocyte proliferation assay. RPMI 1640 supplemented with 10% autologous serum or plasma supported the best antigen driven specific T lymphocyte responses. Using these optimised conditions, we compared the efficacy of PBMC and purified blood DC for priming T lymphocyte responses to the chronic myeloid leukaemia (CML) specific bcr-abl (b3a2) peptide. Peptide specific T lymphocyte responses were generated with both purified DC and whole PBMC, suggesting that T lymphocyte precursor frequency was the limiting factor in these experiments. These results will aid in the generation of human T lymphocyte lines to primary antigens, for in vitro and therapeutic applications.     

Neubau der Langen Brücke in Potsdam

Im vorliegenden Beitrag wird über den Entwurf und die Bauausführung des Neubaus der Langen Brücke in Potsdam berichtet. Im Zuge der verkehrlichen Neugestaltung der Potsdamer Mitte im Zusammenhang mit dem Wiederaufbau des Stadtschlosses wurde dieser Brückenzug in Form zweier sprengwerkartiger Rahmentragwerke als Siegerentwurf eines Wettbewerbes entworfen. Im Ergebnis einer sehr konstruktiven und sympathischen Zusammenarbeit zwischen Ingenieur und Architekt weist der Entwurf ein symbiotisches Gleichgewicht auf zwischen einer technisch innovativen Lösung als integrales Bauwerk mit großer Schlankheit und seiner formalen Ausdrucksweise, die modern ist und zugleich den historischen Bezug herstellt. New building of the Lange Brücke in Potsdam, Germany. The following article describes the construction and conceptual design of the newly built Lange Brücke in Potsdam. The design, which consists of two strutted frame bridges, won first prize in the architecture competition attached to the remodelling of the traffic routing in central Potsdam together with the reconstruction of the Potsdam City Palace. A happy outcome of a constructive and congenial collaboration between engineer and architect, the design succeeds in establishing a symbiotic balance between a technically innovative solution, marked by an exceedingly slender, integral‐type bridge, with a formal mode of expression that, although modern, retains a historical sensitivity.