Small and insular communities are sometimes not served by an efficient Wastewater Treatment Plant, and this is a hazard for both the environment and public health. A wastewater treatment apparatus based on the electrocoagulation process (EC) was tested with municipal wastewater from a small community in Northern Greece with a maximum of 6500 population equivalents. COD decrease was assessed under various parameters: current intensity, time duration, pH and use of Fe or Al electrodes. A simulation of meeting the community’s electricity needs with this apparatus was tested through RETScreen software. The results showed a satisfactory COD decrease through electrocoagulation which was affected by all the parameters mentioned; Fe electrodes could efficiently be used at 300 mA for 60 min for 55% COD removal. It was also shown that a photovoltaic panel system covers the electricity needs of the apparatus, thus no external electricity source is needed for its use. This apparatus could be used effectively by this community, so that the running costs are minimal.

A new study for a boron neutron capture therapy irradiation facility, based on a 2.5 MeV proton accelerator on a thick Li target as neutron converter, is presented here. The beam shaping assembly (BSA) modeling has been performed with the use of the MCNP5 Monte Carlo code. The fast (i.e., > 10 keV) neutron component yielded by the ⁷Li(p,n)⁷Be reaction is slowed down through TiF₃ neutron spectrum shifter, while to obtain a high-quality epithermal neutron beam at the beam port exit additional layers for thermal neutrons removal and shielding of gamma rays were used. Moreover, ⁶⁰Ni and Ti₆Al₁₄V were selected to filter out and further remove the residual fast neutron component, while cadmium was chosen as thermal neutrons absorber, and bismuth was selected for gamma rays shielding. The therapeutic effectiveness of the proposed BSA was evaluated by performing a set of dose-equivalent distribution calculations in a standard Snyder head phantom. The simulation results show that the proposed BSA modeling meets all the recommended by IAEA criteria and provides one possible technical choice for an accelerator-based BNCT irradiation facility in a hospital environment.

A Prompt Gamma Ray Neutron Activation Analysis (PGNAA) system, incorporating an isotopic neutron source has been simulated using the MCNPX Monte Carlo code. In order to improve the signal to noise ratio different collimators and a filter were placed between the neutron source and the object. The effect of the positioning of the neutron beam and the detector relative to the object has been studied. In this work the optimisation procedure is demonstrated for boron. Monte Carlo calculations were carried out to compare the performance of the proposed PGNAA system using four different neutron sources (²⁴¹Am/Be, ²⁵²Cf, ²⁴¹Am/B, and DT neutron generator). Among the different systems the ²⁵²Cf neutron based PGNAA system has the best performance.

Microstructural characteristics and mechanical properties of nano-reinforced cementitious mortar using multi-walled carbon nanotubes (MWCNTs), dispersed in an aqueous solution by applying ultra-solicitation, were studied using X-ray microcomputed tomography (micro-CT), an innovative, non-destructive technique. This useful method was applied for characterizing the cementitious composites’ spatial micro-pore structure. The changes due to the MWCNTs’ integration into the mortar matrix and their effects were studied. The analysis revealed that the density and porosity values processed by micro-CT imaging are crucial parameters. They correlated with the mechanical strength of 2 × 2 × 8 prisms (in cm) in order to evaluate the dispersion effect of the different nanotube concentrations, 0.1 wt.%, 0.2 wt.%, 0.3 wt.%, and 0.5 wt.% by the mass of cement. The results highlight the linear correlation of the density, porosity, and spatial pores’ distribution obtained by the micro-CT 3D in vivo imaging of the microstructure, with the nanotubes’ concentration and flexural and compressive strengths. This investigation was achieved by proving that a deeper understanding of the complex nano- and microstructures can be utilized for the design of advanced cementitious composites at multiple scales.

Fast neutrons that are produced via compact neutron generators have been used for thermal and fast neutron radiographies. In order to investigate objects with different sizes and produce radiographs of variable qualities, the proposed facility has been considered with a wide range of values for the parameters characterizing the thermal and fast neutron radiographies. The proposed system is designed according to article 4 of the Restriction of Hazardous Substances Directive 2002/95/EC, hence, excluded the use of cadmium and lead, and has been simulated using the MCNP4B code. The Monte Carlo calculations were carried out using three different neutron sources: deuterium-deuterium, deuterium-tritium, and tritium-tritium neutron generators.