Guideline for Care of Patients with the Diagnoses of Craniosynostosis: Working Group on Craniosynostosis

This guideline for care of children with craniosynostosis was developed by a national working group with representatives of 11 matrix societies of specialties and the national patients' society. All medical aspects of care for nonsyndromic and syndromic craniosynostosis are included, as well as the social and psychologic impact for the patient and their parents. Managerial aspects are incorporated as well, such as organizing a timely referral to the craniofacial center, requirements for a dedicated craniofacial center, and centralization of this specialized care. The conclusions and recommendations within this document are founded on the available literature, with a grading of the level of evidence, thereby highlighting the areas of care that are in need of high-quality research. The development of this guideline was made possible by an educational grant of the Dutch Order of Medical Specialists. The development of this guideline was supported by an educational grant of the Dutch Order of Medical Specialists

Population Balance Models for Particulate Flows in Porous Media: Breakage and Shear-Induced Events

Transport and particulate processes are ubiquitous in environmental, industrial and biological applications, often involving complex geometries and porous media. In this work we present a general population balance model for particle transport at the pore-scale, including aggregation, breakage and surface deposition. The various terms in the equations are analysed with a dimensional analysis, including a novel collision-induced breakage mechanism, and split into one- and two-particles processes. While the first are linear processes, they might both depend on local flow properties (e.g. shear). This means that the upscaling (via volume averaging and homogenisation) to a macroscopic (Darcy-scale) description requires closures assumptions. We discuss this problem and derive an effective macroscopic term for the shear-induced events, such as breakage caused by shear forces on the transported particles. We focus on breakage events as prototype for linear shear-induced events and derive upscaled breakage frequencies in periodic geometries, starting from nonlinear power-law dependence on the local fluid shear rate. Results are presented for a two-dimensional channel flow and a three dimensional regular arrangement of spheres, for arbitrarily fast (mixing-limited) events. Implications for linearised shear-induced collisions are also discussed. This work lays the foundations of a new general framework for multiscale modelling of particulate flows.Funding: This research has been funded by the Royal Academy of Engineering (Asphaltene dynamics at the pore-scale and the impact on oil production at the field-scale IAPP 18-19 285)

Comparative Life-cycle Assessment of Slurry and Wet Accelerated Carbonation of BOF Slag

This work reports the results of the life cycle assessment (LCA) of two carbonation processes aimed at permanent CO2 storage, employing Basic Oxygen Furnace (BOF) slag from steel manufacturing as alkalinity source. Specifically, the performance of the slurry phase and wet carbonation routes were compared assuming to store the CO2 emitted from a 10 MW conventional natural gas power plant. The LCA was based on the material and energy requirements for each of the involved process steps, i.e. pre-treatment and transport of raw materials, CO2 compression, carbonation, post treatments and management of the obtained products. The slurry and wet route resulted in a net avoided greenhouse warming potential (GWP) of 473 and 384 kg CO2/MWhel, respectively. Nevertheless, both routes affected the other environmental impact categories. In general, the wet route had approximately two times higher impact than the slurry route, due in particular to the higher material and energy requirements. An exception was the abiotic resource depletion which resulted higher for the slurry route due to greater water requirement with respect to the wet route. The contributions to all mid-point impact categories were mainly due to energy requirements. A sensitivity analysis showed that the environmental impacts are affected by the energy mix and by the transport distance of slags and carbonation products

Numerical simulations of aggregate breakup in bounded and unbounded turbulent flows

Breakup of small aggregates in fully developed turbulence is studied by means of direct numerical simulations in a series of typical bounded and unbounded flow configurations, such as a turbulent channel flow, a developing boundary layer, and homogeneous isotropic turbulence. Aggregate breakup occurs when the local hydrodynamic stress $\sigma\sim \varepsilon^{1/2}$, where $\varepsilon$ is the energy dissipation at the position of the aggregate, overcomes a given threshold $\sigma_\mathrm{cr}$, characteristic for a given type of aggregates. Results show that the breakup rate decreases with increasing threshold. For small thresholds, it develops a universal scaling among the different flows. For high thresholds, the breakup rates show strong differences among the different flow configurations, highlighting the importance of non-universal mean-flow properties. To further assess the effects of flow inhomogeneity and turbulent fluctuations, results are compared with those obtained in a smooth stochastic flow. Furthermore, we discuss limitations and applicability of a set of independent proxies