The hydration of slag,part 1: reaction models for alkali-activated slag

Reaction models are proposed to quantify the hydration products and to determine the composition of C–S–H from alkali-activated slags (AAS). Products of the slag hydration are first summarized from observations in literature. The main hydration products include C–S–H, hydrotalcite, hydrogarnet, AFm phases (C₄AH₁₃ and C₂ASH₈) and ettringite. Then, three stoichiometric reaction models are established correlating the mineral composition of slag (the glass part) with the hydration products. Using the proposed models, quantities of hydration products and composition of C–S–H are determined. The models are validated with a number of experimental investigations reported in literature, yielding good agreement, i.e., these models can successfully predict the hydration reaction of AAS. The models are furthermore applied to calculate the retained water in the hydration products of AAS in different hydration states and a general hydration equation of AAS is derived. As an illustration to one of the model applications, chemical shrinkage of the AAS cement paste in different hydration states are predicted. The chemical shrinkage of AAS is shown to be remarkably higher than OPC. Furthermore, phase distribution in the hardened AAS paste and the porosity are calculated.     

The application of inductively coupled plasma mass spectrometry in clinical pharmacological oncology research

Metal-based anticancer agents are frequently used in the treatment of a wide variety of cancer types. The monitoring of these anticancer agents in biological samples is important to understand their pharmacokinetics, pharmacodynamics, and metabolism. In addition, determination of metals originating from anticancer agents is relevant to assess occupational exposure of health care personnel working with these drugs. The high sensitivity of inductively coupled plasma mass spectrometry (ICP-MS) has resulted in an increased popularity of this technique for the analysis of metal-based anticancer drugs. In addition to the quantitative analysis of the metal of interest in a sample, ICP-MS can be used as an ultrasensitive metal selective detector in combination with speciation techniques such as liquid chromatography. In the current review we provide a systematic survey of publications describing the analysis of platinum- and ruthenium-containing anticancer agents using ICP-MS, focused on the determination of total metal concentrations and on the speciation of metal compounds in biological fluids, DNA- and protein-adducts, and environmental samples. We conclude that ICP-MS is a powerful tool for the quantitative analysis of metal-based anticancer agents from multiple sample sources.     

Systematic Review: Targeted Molecular Imaging of Angiogenesis and Its Mediators in Rheumatoid Arthritis

Extensive angiogenesis is a characteristic feature in the synovial tissue of rheumatoid arthritis (RA) from a very early stage of the disease onward and constitutes a crucial event for the development of the proliferative synovium. This process is markedly intensified in patients with prolonged disease duration, high disease activity, disease severity, and significant inflammatory cell infiltration. Angiogenesis is therefore an interesting target for the development of new therapeutic approaches as well as disease monitoring strategies in RA. To this end, nuclear imaging modalities represent valuable non-invasive tools that can selectively target molecular markers of angiogenesis and accurately and quantitatively track molecular changes in multiple joints simultaneously. This systematic review summarizes the imaging markers used for single photon emission computed tomography (SPECT) and/or positron emission tomography (PET) approaches, targeting pathways and mediators involved in synovial neo-angiogenesis in RA.     

Flow analysis of water–powder mixtures: Application to specific surface area and shape factor

This paper addresses the characterization of powder materials with respect to their application in concrete. Given that powders provide by far highest percentage of specific surface area in a concrete mix, their packing behavior and water demand is of vital interest for the design of concrete. They dominate physical properties like workability or strength and durability in hardened state.Regarding the granular properties of powders, different states of packing are analyzed and compared. In reference to water demands, this paper compares and analyzes four different methods, including the spread-flow test. It is shown that linear relations can be derived in order to correlate the methods. Besides comments and modifications to individual tests, the spread-flow test is analyzed in more detail. In this way new measures are derived which contribute to a deeper understanding of wet granular mixtures at the onset of flowing.Furthermore, the deformation coefficient which is derived by the spread-flow test is confirmed to correlate with the product of Blaine surface and intrinsic density of the individual powders when the mixture is flowing only under its own weight. Similarly, correlations with equal accuracy are found with a computed specific surface, based on measured particle size distributions. Using the flow experiments it is possible to derive an overall factor for assessing the non-spherical shape of the powder particles. It is shown that the computed surface area and the Blaine value have a constant ratio (of about 1.7).Finally, the value of a constant water layer thickness around the powder particles is computed for all powders at the onset of flowing. This implies the possibility to predict flow behavior of paste only based on the knowledge of their specific surface area, either determined by computation or Blaine measurements.     

On the early-age behavior of zero-slump concrete

This paper presents experimental investigations and analyses on the early-age-behavior of zero-slump concrete, such as compaction behavior and green-strength. First, the influence of the granulometric properties of the fines is discussed in detail. For this purpose, the early-age behavior of two different fines (quartz flour and fly ash) is investigated by means of the intensive compaction test (IC-test). The tests on the influence of the fines focus on effects caused by differences in the particle shape and the use of a plasticizing admixture. The conducted tests on the compaction behavior of the fines and their corresponding green-strength are extended to continuously graded granular mixes. Here, the influence of optimized particle packing on the early-age behavior is presented and a comparison on the basis of the aforementioned quartz flour and fly ash is made. In this consideration, experimental investigations on the early-age behavior of a zero-slump concrete mix and possible effects on the hardened concrete properties are included.     

Production of non-constructive concrete blocks using contaminated soil

In this research, a heavily contaminated humus-rich peat soil and a lightly contaminated humus-poor sand soil, extracted from a field location in the Netherlands, are immobilized. These two types of soil are very common in the Netherlands. The purpose is to develop financial feasible, good quality immobilisates, which can be produced on large scale.To this end, two binder combinations were examined, namely slag cement with quicklime and slag cement with hemi-hydrate. The mixes with hemi-hydrate proved to be better for the immobilization of humus rich soils, having a good early strength development. The heavily contaminated soil with 19% humus (of dm) could not be immobilized using 398 kg slag cement and 33 kg quicklime per m³ concrete mix (binder = 38.4% dm soil). It is possible to immobilize this soil using 480 kg binder (432 kg slag cement, 48 kg quicklime) per m³ of mix (58.2% dm). An alternative to the addition of extra binder (slag cement with quicklime) is mixing the soil with sand containing particles in the range of 0–2 mm. This not only improved the compressive strength of the immobilisates, but also reduced the capillary absorption. All the mixes with the lightly contaminated soil were cost-effective and suitable for production of immobilisates on a large scale. These mixes had good workability, a good compressive strength and a low capillary absorption. The leaching of all mixes was found to be much lower than allowed by the regulations. Given these results, the final mixes in the main experiment fulfilled all the financial and technical objectives.     

Fly ash reactivity: Extension and application of a shrinking core model and thermodynamic approach

In the present paper a theoretical study is presented on the dissolution (reaction) of pulverised powder coal fly ash. A shrinking core model is derived for hollow spheres that contain two regions (outer hull and inner region). The resulting analytical equations are applied to the dissolution experiments by Pietersen (Mat.Res.Soc.Symp.Proc., Vol. 178, Materials Research Society, 1990, p. 139; Ph.D. Thesis, Delft University of Technology, The Netherlands, 1993), yielding reaction rates at various temperatures and pH for two class F fly ashes. It is revealed that the available amount of reactive fly ash is proportional to the glass content of the fly ash, and that the reaction rate is proportional to this glass content as well. Moreover, it is concluded that the outer region is less reactive than the inner region, and that these reactivities are proportional to a power of the hydroxyl concentration. Subsequently, experimental data and model are used to assess the magnitude of inner and outer region. It seems that the outer hull of solid spheres and cenospheres are having the same thickness, about 2 m. Based on the observed trends a reaction mechanism is proposed which accounts for the glass content and composition of the fly ash (and that is applicable to slags as well). Finally, using the reaction product, thermodynamic properties of the studied fly ashes are derived: the free energy, enthalpy and entropy of reaction.     

Creeping Film Models for Rotating Channels

A theoretical analysis is presented for the development of a liquid film at the walls of vertically placed centrifugal separators. The liquid film arises at the walls of these separators due to the action of the centrifugal force on the entrained liquid phases. The analysis applies to situations, for which the liquid load is small, i.e., the film thickness is much smaller than the height of the channel. This implies that the film can be regarded as a laminar boundary‐layer type flow with negligible inertia effects. Solutions are presented for situations in which the liquid droplets flow co‐currently and counter‐currently with the gas flow.     

Evaluation of energy performance indicators and financial aspects of energy saving techniques in residential real estate

The energy consumption in the existing residential building stock accounts for about 40% of the total energy consumption in the built environment. Different types of energy performance indicators to assess the energy consumption of buildings were and still are internationally under development. In this paper we compare the methodologies and accuracies of three Dutch energy performance indicators by applying them to eight houses. This application shows that the actual domestic energy use is linearly correlated with the estimated energy consumption given by the energy performance indicators, but 7-25% lower.Based on the energy performance indicators and actual energy use, we offer a methodology to incorporate additional revenues within the financial analysis of energy saving techniques. These revenues are related to the value of the dwelling in which the techniques are installed. We use the same houses to analyse the financial returns on energy saving investments. By assigning the value increase of real estate to two popular specific energy saving techniques, namely wall and roof insulation, it is found that the payback period could be 40-50% shorter than when it is solely based on investment costs and energy prices.