The effect of contaminants on the application of polyamine functionalised ion exchange resins for uranium extraction from sulfate based mining process waters

Three in-house produced polyamine functionalised ion exchange resins and Purolite S985 (a commercial ion exchange resin) have been assessed for their ability to extract UO22+ from a variety of aqueous matrices applicable to current and potential future uranium mining processes. The uptake of common contaminant species in uranium processing liquors at variable acid concentrations has been assessed, with Al3+ and MoO42− showing the most extraction, with AsO43−, Eu3+ and Fe3+ showing extractions >10% at low [H+]. Extraction of MoO42−, AsO43−, Eu3+ and Fe3+ was seen to decrease with increasing [H+]. The impact of increasing [Cl−] on UO22+ and Fe3+ extraction has been determined. Fe3+ showed low extractions by all resins, with no dependence on [Cl−]. In contrast, increasing suppression of UO22+ uptake was seen with increasing [Cl−] up to 80 g L−1, with extraction remaining constant beyond this [Cl−]. At high [Cl−] (>50 g L−1) Purolite S985 was seen to remove UO22+ from solution more effectively than all synthesised polyamine resins. The presence of Fe3+ in solution was seen to suppress UO22+ uptake by around 10% when [Fe3+]/[UO22+] increased from 0 to 2. Fe3+ extraction by all studied resins was promoted by the presence of UO22+ in solution. This was most prevalent with Purolite S985, with an extraction of 30% for [Fe3+]/[UO22+] = 2 by Purolite S985. All resins were tested using a process water from a uranium mine and have shown an ability to selectively extract UO22+ from such solutions, with the best synthetic resin recovering 15.7% more uranium than Purolite S985

XEN gel stent: A total delayed-onset postoperative hyphema

cited By

Obstructed MIGS

International audienc

Hybrid AC-DC standalone system based on PV array and wind turbine

This paper presents a new topology of hybrid AC-DC standalone system based on solar photo-voltaic (PV) array and wind turbine (WT) feeding three-phase four-wire loads. The proposed hybrid system employs two back to back converters and dc-dc boost converter to achieve maximum power point tracking (MPPT). To balance the power at the PCC, the system is reinforced by BESS (Battery Energy Storage System) to keep constant frequency and voltage and to improve the power quality. The dump load is added to the system and is placed at the common dc bus to manage the extra power when the battery is fully charged. The capacitor bank is used to provide the reactive power to the doubly fed induction generator (DFIG). The proposed system is studied for various types of linear, nonlinear and dynamic loads and under varying climate conditions. The dynamic behavior of the proposed system is verified using MATLAB/Simulink

Hypertensive choroidopathy: Multimodal imaging and the contribution of wide-field swept-source oct-angiography

cited By 0Purpose: To present the case of a patient with a hypertensive choroidopathy and her follow-up using multimodal imaging; and to assess how wide-field swept-source (SS) Optical Coherence Tomography Angiography (OCTA) contributes to detecting the areas of hypoperfusion. Observations: A 25-year-old white woman with terminal renal insufficiency, myopericarditis, and cerebrospinal fluid pressure of 37 mmHg indicating intracranial hypertension, presented with a painless loss of vision in both eyes. Her blood pressure was 190/135 mmHg. A thorough diagnosis work-up failed to reveal the etiology. The fundus examination showed arterial narrowing and moderate venous dilation in both eyes. Deep yellow spots were found bilaterally, associated with slight pigment epithelium detachments and exudative retinal detachments. Multimodal imaging showed characteristic features of choroidal involvement in hypertension. Wide-field 12 × 12 mm PlexElite map montage at the choriocapillaris slab identified areas of non-perfusion of the choriocapillaris. These areas mostly correlate with late indocyanine green angiography (ICGA)-presumed choroidal ischemia. During the follow-up, the patient's blood pressure normalized and the choriocapillaris flow improved. Conclusions and importance: In this case of malignant hypertensive retinopathy with exudative retinal detachment of the posterior pole, SS-OCTA showed multiple and widespread flow voids on the choriocapillaris slabs, corresponding to the areas of hypofluorecence on ICGA, demonstrating an associated hypertensive choroidopathy. It would appear that SS-OCTA used alone is capable to show choroidal vascularization impairment in cases of hypertensive retinopathy. © 201

A bleeding MIGS

International audienc

Hybrid standalone power generation system using hydro-PV-battery for residential green buildings

This paper deals with control of hybrid standalone power generation using micro-hydro power turbine (MHP) coupled with a squirrel cage induction generator (SCIG) and a solar photovoltaic panel (PV), which is connected to the common DC bus of three-phase voltage source converter (VSC). The AC terminals of VSC are connected to point of common coupling (PCC) through interface inductors. A battery energy storage system (BESS) is also tied with the common DC bus through a buck-boost converter. The proposed system is mostly suitable to serve the power needs of any small size residential green building situated near a small river or cannel. Control algorithms are proposed for the three-phase VSC and the DC-DC buck-boost converter in order to extract the maximum power from PV array with single-stage conversion, to regulate the AC voltage and frequency at PCC and to improve the power quality. The effectiveness and the robustness of proposed controllers are validated by simulation using Matlab/Simulink at linear and nonlinear loads under different climate conditions