Over the past decade, the Belgian nuclear research centre (SCK CEN) has gathered extensive laboratory data on diffusion coefficients of dissolved gases in water-saturated Boom Clay (BC). Since gas transport around a geological disposal facility occurs at metre scales, a key question is whether centimetre-scale laboratory values remain valid under in situ conditions. To address this, SCK CEN, EURIDICE, and ONDRAF/NIRAS launched the NEMESIS (NEon diffusion in MEgaS In-Situ) experiment in September 2023 at the HADES Underground Research Laboratory in Belgium. Its purpose is to confirm and refine understanding of gas diffusion in BC at realistic scales. NEMESIS reuses four piezometers from the 1990s MEGAS experiment. Dissolved neon is injected into the clay through a vessel–microtube–filter system, and its migration is monitored at three observation filters. This paper outlines the experimental design, strategy, initial findings, and early interpretations. The setup has proven effective under in situ conditions and provides new insights into the coupling between diffusion and water flow. Preliminary best-fit diffusion coefficients from Phase 1 (in-diffusion) are broadly consistent with laboratory measurements. Phase 2 (through-diffusion), to be conducted over the coming years, will deliver additional data to validate results, refine interpretations, and strengthen the characterisation of gas diffusion in Boom Clay.
Effective conservation practice requires decisions based on reliable and relevant evidence, but significant gaps in the evidence base exist. Incorporating well-designed tests of the effectiveness of interventions for biodiversity in conservation projects is one of the best ways to scale up the rate of evidence generation. Funders of conservation projects are uniquely positioned to support and incentivize such tests as part of the grant-making process. Using a structured process, as 25 conservation funders and members of Conservation Evidence, we identified means of improving the effectiveness of the work funded through the support of enhanced evidence generation. We identified 11 approaches through which funders can support embedding testing, ranging from encouraging inclusion of a test in the project proposal, to designating separate funds for incorporating a test, to supporting an external testing unit to provide training and advice. The appropriate approaches vary depending on the scale, process, and type of funding. Barriers to supporting testing and potential solutions were discussed, barriers such as a lack of skills to check tests are appropriate and well designed and the additional time needed to develop, implement, and see outcomes of tests and differing types of projects. By encouraging testing of actions as part of conservation practice (where appropriate), funders will ultimately facilitate a stronger evidence base for more effective decision-making and better outcomes for nature and society.
Radioactive waste geological disposal is considered as a feasible and safe solution, but requires detailed understanding of the interactions between the radionuclides and the components of the disposal system. A key process limiting the mobility of radionuclides is sorption, which determines how these elements interact with solid phases such as clay and cement within geological and engineered barriers. Effective management of sorption data is required to improve traceability and confidence in safety analyses and to demonstrate the long-term safety of the repository. Sorption is classically determined by means of sorption experiments (e.g. isotherms, edges) and related thermodynamic sorption modelling. Extensive knowledge is already available in the scientific literature for the sorption of many radionuclides and toxic contaminants onto relevant solid phases. Sorption is known to be system specific and strongly dependent on the chemical conditions (e.g. ligand concentrations, redox conditions, pH). Sorption databases provide a sound framework for recording all relevant information and are expected to provide a robust basis for making good use of the knowledge in the safety case. This paper presents the development and current status of a sorption database system tailored to the specific needs of the Belgian programme, in particular disposal in poorly indurated clays (i.e. Boom Clay and Ypresian clays).
Abstract We report results from a large-scale randomized controlled trial aimed at empowering young women during the transition from secondary school. The trial includes four school-based arms: economic empowerment, reproductive health empowerment, their combination, and a control group. The analysis draws on a rich dataset combining survey and laboratory measures collected over more than five years. The economic program increased self-employment and income, while the reproductive health program strengthened self-control and increased committed relationships. Both interventions also increased early pregnancy, which we attribute to positive income and relationship effects in a context characterized by high fertility and self-employment.
Cross-laminated timber (CLT) has gained popularity in recent years. However, there are several indications that it has poor sound insulation and current prediction models are not suitable for this lightweight material. In this project is investigated a vibro-acoustic prediction model for impact sound insulation of CLT floor elements, using the finite element model (FEM) software, COMSOL. The material properties of a CLT floor element have been analyzed through multiple experimental investigations and compared to literature. Several modal analyses have been made and compared between measured and numerically found natural frequencies and mode shapes; in order to validate the model of the CLT material, the floors junction and the boundary conditions of the lab. Finally, the FEM has been tuned to achieve the best possible fit with the measured impact sound insulation of the same floor.
