3 research outputs found

    Optimization of organic meso-superstructured solar cells for underwater IoT² self-powered sensors

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    The effectiveness of the mesoporous TiO₂ layer, which acts as an active n-type semiconductor layer in dye-sensitized solar cells (DSSCs), was investigated by varying AgVO₃ doping. To optimize the meso-superstructure, the doping concentration was varied from 0% to 25% using experimentally validated simulations. Moreover, performance comparisons between the experimentally fabricated DSSCs based on natural beetroot dye and the commonly used N719 dye were made. A 15% doping concentration was found optimum for our DSSC, which delivered an output power of 19.24 mW, 6.1% power conversion efficiency, and an open-circuit voltage, Voc , of 0.5 V and a short-circuit current density, Jsc , of 21 mA/cm² in diffused light conditions. Based on these performance results, we integrated our optimized DSSC in an underwater sensing unit as a light harvester

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Boosting dye-sensitized solar cell efficiency using AgVO3-doped TiO2 active layer

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    Dye-sensitized solar cells have shown great potential in low and self-powered nano/micro-scale applications, due to their low fabrication costs, semi-transparency in the visible spectrum, diffused light harvesting capabilities, and their lead-free structure. However, DSSC efficiencies are still relatively low due to their limited absorption capabilities in the active mesoporous layer. The current study demonstrates an attempt to boost the overall conversion efficiency of DSSC by narrowing the energy band gap of the mesoporous TiO2 active layer. AgVO3 is utilized in doping the mesoporous layer, seeking for a visible absorption shift from 3.2 eV to 2.6 eV. In addition, natural organic beetroot dye is used while keeping DSSC with N719 dye as a bare cell. Morphological, optical, as well as electrical characterization results were obtained for both thin-film and complete solar cells. The fabricated cell showed an overall harvested power density of 8.6 mW/cm2, capable of operating various low-power sensing applications
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