Enhancement of TiO2 nanoparticle properties and efficiency of dye-sensitized solar cells using modifiers

A low-temperature hydrothermal process developed to synthesizes titania nanoparticles with controlled size. We investigate the effects of modifier substances, urea, on surface chemistry of titania (TiO) nanopowder and its applications in dye-sensitized solar cells (DSSCs). Treating the nanoparticles with a modifier solution changes its morphology, which allows the TiO nanoparticles to exhibit properties that differ from untreated TiO nanoparticles. The obtained TiO nanoparticle electrodes characterized by XRD, SEM, TEM/HRTEM, UV-VIS Spectroscopy and FTIR. Experimental results indicate that the effect of bulk traps and the surface states within the TiO nanoparticle films using modifiers enhances the efficiency in DSSCs. Under 100-mW cm simulated sunlight, the titania nanoparticles DSSC showed solar energy conversion efficiency = 4.6 %, with V = 0.74 V, J = 9.7324 mA cm, and fill factor = 71.35

Groin wound infection after vascular exposure ( GIVE ) multicentre cohort study

Surgical site infections (SSIs) of groin wounds are a common and potentially preventable cause of morbidity, mortality, and healthcare costs in vascular surgery. Our aim was to define the contemporaneous rate of groin SSIs, determine clinical sequelae, and identify risk factors for SSI. An international multicentre prospective observational cohort study of consecutive patients undergoing groin incision for femoral vessel access in vascular surgery was undertaken over 3 months, follow‐up was 90 days. The primary outcome was the incidence of groin wound SSI. 1337 groin incisions (1039 patients) from 37 centres were included. 115 groin incisions (8.6%) developed SSI, of which 62 (4.6%) were superficial. Patients who developed an SSI had a significantly longer length of hospital stay (6 versus 5 days, P = .005), a significantly higher rate of post‐operative acute kidney injury (19.6% versus 11.7%, P = .018), with no significant difference in 90‐day mortality. Female sex, Body mass index≥30 kg/m2, ischaemic heart disease, aqueous betadine skin preparation, bypass/patch use (vein, xenograft, or prosthetic), and increased operative time were independent predictors of SSI. Groin infections, which are clinically apparent to the treating vascular unit, are frequent and their development carries significant clinical sequelae. Risk factors include modifiable and non‐modifiable variables

Cohort Profile: Burden of Obstructive Lung Disease (BOLD) study

The Burden of Obstructive Lung Disease (BOLD) study was established to assess the prevalence of chronic airflow obstruction, a key characteristic of chronic obstructive pulmonary disease, and its risk factors in adults (≥40 years) from general populations across the world. The baseline study was conducted between 2003 and 2016, in 41 sites across Africa, Asia, Europe, North America, the Caribbean and Oceania, and collected high-quality pre- and post-bronchodilator spirometry from 28 828 participants. The follow-up study was conducted between 2019 and 2021, in 18 sites across Africa, Asia, Europe and the Caribbean. At baseline, there were in these sites 12 502 participants with high-quality spirometry. A total of 6452 were followed up, with 5936 completing the study core questionnaire. Of these, 4044 also provided high-quality pre- and post-bronchodilator spirometry. On both occasions, the core questionnaire covered information on respiratory symptoms, doctor diagnoses, health care use, medication use and ealth status, as well as potential risk factors. Information on occupation, environmental exposures and diet was also collected

Enhancement of TiO2 nanoparticle properties and efficiency of dye-sensitized solar cells using modifiers

A low-temperature hydrothermal process developed to synthesizes titania nanoparticles with controlled size. We investigate the effects of modifier substances, urea, on surface chemistry of titania (TiO) nanopowder and its applications in dye-sensitized solar cells (DSSCs). Treating the nanoparticles with a modifier solution changes its morphology, which allows the TiO nanoparticles to exhibit properties that differ from untreated TiO nanoparticles. The obtained TiO nanoparticle electrodes characterized by XRD, SEM, TEM/HRTEM, UV-VIS Spectroscopy and FTIR. Experimental results indicate that the effect of bulk traps and the surface states within the TiO nanoparticle films using modifiers enhances the efficiency in DSSCs. Under 100-mW cm simulated sunlight, the titania nanoparticles DSSC showed solar energy conversion efficiency = 4.6 %, with V = 0.74 V, J = 9.7324 mA cm, and fill factor = 71.35

Prediction of concrete compressive strength due to long term sulfate attack using neural network

This work was divided into two phases. Phase one included the validation of neural network to predict mortar and concrete properties due to sulfate attack. These properties were expansion, weight loss, and compressive strength loss. Assessment of concrete compressive strength up to 200 years due to sulfate attack was considered in phase two. The neural network model showed high validity on predicting compressive strength, expansion and weight loss due to sulfate attack. Design charts were constructed to predict concrete compressive strength loss. The inputs of these charts were cement content, water cement ratio, C3A content, and sulfate concentration. These charts can be used easily to predict the compressive strength loss after any certain age and sulfate concentration for different concrete compositions

Tailoring green formulation : printing and upscaling of inverted organic solar cells

By tailoring the solvents of active organic solar cell layers regarding their solubility (Hansen parameters), non-halogenated solvents and solvent mixtures can be used to print the active layers of organic solar cells. Similar efficiencies to other typical laboratory methods as spin-coating can be reached. Furthermore, using sheet-to-sheet printing or coating techniques compatible to mass-manufacturing and structuring by laser ablation, we can upscale to 10x20 cm(2) and manufacture modules on plastic substrates. This is a breakthrough for organic solar cells and the next important step on the way to utilize organic solar cells for industrial manufacturing