Separation of Ho3+ in Static Magnetic Field

Abstract The rare earths elements (REE) belong to the group of critical metals and they are achieving more and more interest due to their special properties. However, there occur some problems connected with their production. The most difficult phase is separation of REE. It includes a necessity to intensify currently applied processes and looking for new solutions. The present work introduces an idea to use differences in physical properties of the REE ions to get them separated. In the experimental part of the work some efforts were undertaken to analyse results presenting changes of holmium ions concentration under an influence of the magnetic field gradient. There was determined the gradient of magnetic field and concentration of Ho3+ ions depending on initial concentration of the solution and time. A simulation of changing the concentration of holmium ions in the solution under an influence of the magnetic field gradient was performed to compare the mathematical model with the obtained results

Ru–Co alloy coatings electrodeposited on a MAX phase substrate as efficient catalysts for the hydrogen evolution reaction

This study investigates the structure, electrochemical behavior and hydrogen evolution reaction (HER) performance of electrodeposited Ru–Co alloy coatings. The alloys were prepared from a 0.75 M Co2+ + 0.025 M Ru3+ solution at various potentials ranging from −0.5 to −1.2 V vs. SCE. Results reveal that the Ru and Co deposition processes are interdependent. The deposition of nobler Ru from the mixed metal solution reaches pure diffusion control already at −0.7 V compared to −1.0 V from a single Ru bath. On the other hand, Co deposition is significantly facilitated in the presence of Ru in the solution. Consequently, as the deposition potential changes from −0.6 to −1.0 V, Ru–Co solid solution coatings characterized by a distinct globular morphology are formed, with their Co content increasing from 22.1/7.4 to 70.2/86.1 wt% for the Cu/Ti2AlC MAX phase substrate applied. The alloy catalysts are found to show much better HER activity and stability in alkaline than in acidic solutions. The best Ru–Co@Ti2AlC sample, electrodeposited at −0.6 V, requires an overpotential of only −95 mV to deliver a current density of −100 mA cm−2 in 1 M KOH, thus outperforming most Ru–Co-based HER electrocatalysts reported to date

Developing a standard approach for assessing the hydromorphology of lakes in Europe

International audience1. Methods for assessing the hydrology and morphology of lakes ('hydromorphology') are needed for reporting under national and international legislation, as well as to assist in lake management and restoration. Despite this, no consistent approaches have been developed around Europe for monitoring lake hydromorphology. 2. To address this need, representatives from 12 countries met at a series of workshops to develop two protocols for monitoring, published under the auspices of the European Committee for Standardization (CEN). The first standard (EN 16039) describes six categories for assessing lake hydromorphology: hydraulics, morphometry, bedforms/landforms and substrate, connectivity and continuity, and land cover. The second standard (EN 16870) sets out a scoring system for assessing the degree of modification of lake hydromorphology, which was designed, tested and refined using data from 127 lakes in seven European countries. 3. The CEN standards focus on four lake zones: riparian, shore, littoral, and open water, but recognize the importance of considering lakes within their wider catchment context. The field techniques described are based largely on Lake Habitat Survey (LHS) but also rely on existing databases, maps and remote sensing data. 4. These standards are aimed at scientists, conservation bodies and environmental regulators, and are relevant not only for monitoring lakes under the WFD, but also for contributing to programmes of lake conservation. For example, in the UK, parts of the CEN standards have been incorporated within the methods used for monitoring and reporting on the condition of Special Areas of Conservation (under the Habitats Directive) and Sites of Special Scientific Interest under national legislation

Status and initial physics performance studies of the MPD experiment at NICA

The Nuclotron-based Ion Collider fAcility (NICA) is under construction at the Joint Institute for Nuclear Research (JINR), with commissioning of the facility expected in late 2022. The Multi-Purpose Detector (MPD) has been designed to operate at NICA and its components are currently in production. The detector is expected to be ready for data taking with the first beams from NICA. This document provides an overview of the landscape of the investigation of the QCD phase diagram in the region of maximum baryonic density, where NICA and MPD will be able to provide significant and unique input. It also provides a detailed description of the MPD set-up, including its various subsystems as well as its support and computing infrastructures. Selected performance studies for particular physics measurements at MPD are presented and discussed in the context of existing data and theoretical expectations