Deep Eutectic Solvents Based on N-Methylacetamide and a Lithium Salt as Electrolytes at Elevated Temperature for Activated Carbon-Based Supercapacitors

<p class="articleBody_abstractText">This study describes the utilization of deep eutectic solvents (DESs) based on the mixture of the <i>N-methylacetamide (MAc) with a lithium salt (LiX, with X = bis[(trifluoromethyl)sulfonyl]imide, TFSI; hexafluorophosphate, PF₆; or nitrate, NO₃) as electrolytes for carbon-based supercapacitors at 80 ��C. The investigated DESs were formulated by mixing a LiX with the MAc (at <i>x</i>_Li = 0.25). All DESs show the typical eutectic characteristic with eutectic points localized in the temperature range from ���85 to ���52 ��C. Using thermal properties measured by differential scanning calorimetry (DSC), solid���liquid equilibrium phase diagrams of investigated LiX���MAc mixtures were then depicted and also compared with those predicted by using the COSMOThermX software. However, the transport properties of selected DESs (such as the conductivity (��) and the fluidity (��^���1)) are not very interesting at ambient temperature, while by increasing the temperature up to 80 ��C, these properties become more favorable for electrochemical applications, as shown by the calculated Walden products: <i>w</i> = ����^���1 (mS cm^���1 Pa^���1 s^���1) (7 &lt; <i>w</i> &lt; 16 at 25 ��C and 513 &lt; <i>w</i> &lt; 649 at 80 ��C). This ���superionicity��� behavior of selected DESs used as electrolytes explains their good cycling ability, which was determined herein by cyclic voltammetry and galvanostic charge���discharge methods, with high capacities up to 380 F g^���1 at elevated voltage and temperature, i.e., ��<i>E</i> = 2.8 V and 80 ��C for the LiTFSI���MAc mixture at <i>x</i>_Li = 0.25, for example. The electrochemical resistances ESR (equivalent series resistance) and EDR (equivalent diffusion resistance) evaluated using electrochemical impedance spectroscopy (EIS) measurements clearly demonstrate that according to the nature of anion, the mechanism of ions adsorption can be described by pure double-layer adsorption at the specific surface or by the insertion of desolvated ions into the ultramicropores of the activated carbon material. The insertion of lithium ions is observed by the presence of two reversible peaks in the CVs when the operating voltage exceeds 2 V. Finally, the efficiency and capacitance of symmetric AC/AC systems were then evaluated to show the imbalance carbon electrodes caused by important lithium insertion at the negative and by the saturation of the positive by anions, both mechanisms prevent in fact the system to be operational. Considering the promising properties, especially their cost, hazard, and risks of these DESs series, their introduction as safer electrolytes could represent an important challenge for the realization of environmentally friendly EDLCs operating at high temperature.</i></p>

A simple and low-cost method for the preparation of self-supported TiO₂-WO₃ ceramic heterojunction wafers

<p>Robust, bilayer heterojunction photodiodes of TiO₂-WO₃ were prepared successfully by a simple, low-cost powder pressing technique followed by heat-treatment. Exclusive photoirradiation of the TiO₂ side of the photodiode resulted in a rapid colour change (dark blue) on the WO₃ surface as a result of reduction of W⁶⁺ to W⁵⁺ (confirmed by X-ray photoelectron spectroscopy). This colour was long lived and shown to be stable in a dry environment in air for several hours. A similar photoirradiation experiment in the presence of a mask showed that charge transfer across the heterojunction occurred approximately normal to the TiO₂ surface, with little smearing out of the mask image. As a result of the highly efficient vectorial charge separation, the photodiodes showed a tremendous increase in photocatalytic activity for the degradation of stearic acid, compared to wafers of the respective individual materials when tested separately.</p>

Gaussian pulse mixing by stacked semiconductor layers

<p>The nonlinear scattering of two Gaussian pulses with different central frequencies incident at slant angles on the periodic stack of binary semiconductor layers has been modelled in the self-consistent problem formulation taking into account the dynamics of charges. The effects of the pump pulse length and central frequencies, and the stack physical and geometrical parameters on the properties of the emitted combinatorial frequency waveforms are analysed and discussed.</p>

Cost-effectiveness of tooth replacement strategies for partially dentate elderly: a randomized controlled clinical trial

<p>OBJECTIVE: To conduct a cost-effectiveness analysis comparing two different tooth replacement strategies for partially dentate older patients, namely partial removable dental prostheses (RDP) and functionally orientated treatment based on the shortened dental arch concept (SDA).</p><p>METHODS: Ninety-two partially dentate older patients completed a randomized controlled clinical trial. Patients were randomly allocated to two treatment groups: the RDP group and the SDA group. Treatment effect was measured using impact on oral health-related quality of life (OHrQOL), and the costs involved in providing and maintaining care were recorded for all patients. Patients were followed for 12 months after treatment intervention. All treatment was provided by a single operator.</p><p>RESULTS: The total cost of achieving the minimally important clinical difference (MID) in OHrQOL for an average patient in the RDP group was ���464.64. For the SDA group, the cost of achieving the MID for an average patient was ���252.00. The cost-effectiveness ratio was therefore 1:1.84 in favour of SDA treatment.</p><p>CONCLUSION: With an increasingly ageing population, many patients will continue to benefit from removable prostheses to replace their missing natural teeth. From a purely economic standpoint, the results from this analysis suggest that the treatment of partially dentate older adults should be focused on functionally orientated treatment because it is simply more cost-effective.</p>

Cost-effectiveness of ART restorations in elderly adults: a randomized clinical trial

<p>BACKGROUND: As the world population ages, the requirement for cost-effective methods of treating chronic disease conditions increases. In terms of oral health, there is a rapidly increasing number of dentate elderly with a high burden of maintenance. Population surveys indicate that older individuals are keeping their teeth for longer and are a higher caries risk group. Atraumatic Restorative Treatment (ART) could be suitable for patients in nursing homes or house-bound elderly, but very little research has been done on its use in adults.</p><p>OBJECTIVES: To compare the cost-effectiveness of ART and a conventional technique (CT) for restoring carious lesions as part of a preventive and restorative programme for older adults.</p><p>METHODS: In this randomized clinical trial, 82 patients with carious lesions were randomly allocated to receive either ART or conventional restorations. Treatment costs were measured based on treatment time, materials and labour. For the ART group, the cost of care provided by a dentist was also compared to the cost of having a hygienist to provide treatment. Effectiveness was measured using percentage of restorations that survived after a year.</p><p>RESULTS: Eighty-two patients received 260 restorations, that is, 128 ART and 132 conventional restorations. 91.1% of the restorations were on one surface only. After a year, 252 restorations were assessed in 80 patients. The average cost for ART and conventional restorations was ���16.86 and ���28.71 respectively; the restoration survival percentages were 91.1% and 97.7%, respectively. This resulted in a cost-effectiveness ratio of 0.18 (ART) and 0.29 (CT). When the cost of a hygienist to provide ART was inserted in the analysis, the resulting ratio was 0.14.</p><p>CONCLUSIONS: Atraumatic restorative treatment was found to be a more cost-effective alternative to treat older adults after 1 year, compared to conventional restorations, especially in out of surgery facilities and using alternative workforce such as hygienists. Atraumatic restorative treatment can be a useful tool to provide dental care for frail and fearful individuals who might not access dental treatment routinely.</p>

A preliminary report of the cost-effectiveness of tooth replacement strategies for partially dentate elders

<p>OBJECTIVE: To compare the cost-effectiveness of conventional treatment using partial dentures with functionally orientated treatment to replace missing teeth for partially dentate elders using a randomised controlled clinical trial.</p><p>BACKGROUND: In many countries, including the Republic of Ireland, the only publically funded treatment option offered to partially dentate older patients is a removable partial denture. However, evidence suggests that these removable prostheses are unpopular with patients and can potentially increase the risk of further dental disease and subsequent tooth loss.</p><p>MATERIALS AND METHODS: Fourty-four partially dentate patients aged 65 years and older were recruited. Patients were randomly assigned to the two treatment arms of the study. The conventional treatment group received removable partial dentures to replace all missing natural teeth. The functionally orientated group was restored to a Shortened Dental Arch (SDA) of 10 occluding contacts using resin-bonded bridgework (RBB). The costs associated with each treatment were recorded. Effectiveness was measured in terms of the impact on oral health-related quality of life (OHRQoL) using OHIP-14.</p><p>RESULTS: Both groups reported improvements in OHRQoL 1 month after completion of treatment. The conventional treatment group required 8.3 clinic visits as compared to 4.4 visits for the functionally orientated group. The mean total treatment time was 183 min 19 s for the conventional group vs. 124 min 8 s for the functionally orientated group. The average cost of treatment for the conventional group was 487.74 Euros compared to 356.20 Euros for the functional group.</p><p>CONCLUSIONS: Functionally orientated treatment was more cost-effective than conventional treatment in terms of treatment effect and opportunity costs to the patients' time.</p>

A cluster randomised controlled trial evaluation and cost-effectiveness analysis of the Roots of Empathy schools-based programme for improving social and emotional wellbeing outcomes among 8-9 year olds in Northern Ireland

A substantial body of evidence suggest that well designed school based prevention programmes can be effective in improving a variety of social, health and academic outcomes for children and young people. This poster presents the methodology for evaluating the Roots of Empathy (ROE) programme. ROE is a universal programme delivered on a whole-class basis for one academic year. It consists of 27 lessons that run over a school year and is based around a monthly classroom visit by an infant and parent, typically recruited from the local community, whom the class 'adopts' at the start of the school year. The evaluation aims to evaluate the immediate and longer term impact of ROE on social and emotional wellbeing outcomes among 8-9 year old pupils, as well as evaluate the cost-effectiveness of the programme.