Molecular landscapes of human hematopoietic stem cells in health and leukemia.

Blood cells are organized as a hierarchy with hematopoietic stem cells (HSCs) at the root. The advent of genomic technologies has opened the way for global characterization of the molecular landscape of HSCs and their progeny, both in mouse and human models, at the genetic, transcriptomic, epigenetic, and proteomics levels. Here, we outline our current understanding of the molecular programs that govern human HSCs and how dynamic changes occurring during HSC differentiation are necessary for well-regulated blood formation under homeostasis and upon injury. A large body of evidence is accumulating on how the programs of normal hematopoiesis are modified in acute myeloid leukemia, an aggressive adult malignancy driven by leukemic stem cells. We summarize these findings and their clinical implications.The authors would like to thank Emily Calderbank for critical review of the manuscript. Research in EL laboratory is supported by a Wellcome Trust Sir Henry Dale Fellowship and core support grant from the Wellcome Trust and MRC to the Wellcome Trust – Medical Research Council Cambridge Stem Cell Institute.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/nyas.1298

Effects of aggregate size on alkali-silica-reaction induced expansion

The macroscopic effects of ASR are linked to the damage state at the microstructure level. In this paper we used a combination of experiments and modelling to study the effect of aggregate size on the manifestation of ASR. There are two main ways in which the size of the aggregates can affect damage evolution: the propagation of cracks in aggregates of different sizes and the interactions between expanding and non-expanding aggregates in a densely packed microstructure. To assess these effects, concretes were cast with the same PSD but each with a different size class of reactive aggregates. Numerical simulations were used to model the mechanical interactions in single aggregates and in complete microstructures at the mesoscopic level. From the simulations a mechanism is proposed to explain the experimental observations. This suggests that: the expansion rate of ASR affected concrete depends on the fracture behaviour of individual aggregates in the early stage, and on the fracture behaviour of the paste in the later stages. (C) 2012 Elsevier Ltd. All rights reserved

Effects of uniaxial stress on alkali-silica reaction induced expansion of concrete

ASR affected concrete in real structures is usually subject to loads which affect the macroscopic expansion of the material. An experimental study was undertaken using sensors embedded in reactive and non-reactive samples loaded on modified creep frames. Numerical analysis was used to link micro-structural damage under the load to expansion. We show that load influences the micro-crack propagation, which changes the shape of the expansion curve. (C) 2011 Elsevier Ltd. All rights reserved

Physically based models to study the alkali-silica reaction

The Laboratory of Construction Materials in Lausanne has been studying the alkali-silica reaction for more than 10 years, advancing the understanding of the reaction, and also producing microstructural models which can be used to predict quantitatively the degradation of affected concrete. This paper provides an overview of these developments. The authors present experimental evidence of the link between aggregate degradation and expansion, a formulation of the microstructural model and a proposition for a macrostructural model derived from their computations

Electric recycling of Portland cement at scale

Acknowledgements: This work was supported in part by EPSRC (grant EP/S019111/1, UK FIRES and grant EP/W026104/1, Cambridge Electric Cement) and Innovate UK (grant G116761, Cement2Zero).Cement production causes 7.5% of global anthropogenic CO2 emissions, arising from limestone decarbonation and fossil-fuel combustion1–3. Current decarbonation strategies include substituting Portland clinker with supplementary materials, but these mainly arise in emitting processes, developing alternative binders but none yet promises scale, or adopting carbon capture and storage that still releases some emissions4–8. However, used cement is potentially an abundant, decarbonated feedstock. Here we show that recovered cement paste can be reclinkered if used as a partial substitute for the lime–dolomite flux used in steel recycling nowadays. The resulting slag can meet existing specifications for Portland clinker and can be blended effectively with calcined clay and limestone. The process is sensitive to the silica content of the recovered cement paste, and silica and alumina that may come from the scrap, but this can be adjusted easily. We show that the proposed process may be economically competitive, and if powered by emissions-free electricity, can lead to zero emissions cement while also reducing the emissions of steel recycling by reducing lime flux requirements. The global supply of scrap steel for recycling may treble by 2050, and it is likely that more slag can be made per unit of steel recycled. With material efficiency in construction9, 10, future global cement requirements could be met by this route

Electric recycling of Portland cement at scale

Acknowledgements: This work was supported in part by EPSRC (grant EP/S019111/1, UK FIRES and grant EP/W026104/1, Cambridge Electric Cement) and Innovate UK (grant G116761, Cement2Zero).Cement production causes 7.5% of global anthropogenic CO2 emissions, arising from limestone decarbonation and fossil-fuel combustion1–3. Current decarbonation strategies include substituting Portland clinker with supplementary materials, but these mainly arise in emitting processes, developing alternative binders but none yet promises scale, or adopting carbon capture and storage that still releases some emissions4–8. However, used cement is potentially an abundant, decarbonated feedstock. Here we show that recovered cement paste can be reclinkered if used as a partial substitute for the lime–dolomite flux used in steel recycling nowadays. The resulting slag can meet existing specifications for Portland clinker and can be blended effectively with calcined clay and limestone. The process is sensitive to the silica content of the recovered cement paste, and silica and alumina that may come from the scrap, but this can be adjusted easily. We show that the proposed process may be economically competitive, and if powered by emissions-free electricity, can lead to zero emissions cement while also reducing the emissions of steel recycling by reducing lime flux requirements. The global supply of scrap steel for recycling may treble by 2050, and it is likely that more slag can be made per unit of steel recycled. With material efficiency in construction9, 10, future global cement requirements could be met by this route

Mapping material use and modelling the embodied carbon in UK construction

The dataset present assumptions and results for the papers "Mapping material use and embodied carbon in the UK construction'' and "Modelling the embodied carbon cost of UK domestic building construction: Today to 2050

An algorithm to compute damage from load in composites

We present a new method to model fracture of concrete based on energy minimisation. The concrete is considered on the mesoscale as composite consisting of cement paste, aggregates and micro pores. In this first step, the alkali-silica reaction is taken into account through damage mechanics though the process is more complex involving thermo-hygro-chemo-mechanical reaction. We use a non-local damage model that ensures the well-posedness of the boundary value problem (BVP). In contrast to existing methods, the interactions between degrees of freedom evolve with the damage evolutions. Numerical results are compared to analytical and experimental results and show good agreement