Dye Sensitized Solar Cells Based on Hydrazonoyl Synthetic Dyes

A group of chemical sensitizers of two hydrazonoyl based derivatives were synthesized. These derivatives contain a good π system for efficient light absorption and oxide sensitization. Precursor structure I was reacted with 2,6-diaminopyridine, 2-aminobenzoic acid, 4-aminobenzoic acid, 2-aminopyridine, 2,6-dinitrophenylhydrazine, and diphenylamine. The other precursor, structure (II), was reacted with 2-aminobenzoic acid, 2-amino-3-methyl, and 2-amino-4-methylpyridine. A total of 9 dyes were prepared and evaluated as sensitizers for dye-sensitized solar cells (DSSCs). Full computational calculations using DFT B3LYP 6-31+G were carried out for evaluation of band edge and band gap energies of all compounds. The absorption spectra of these dyes as well as cyclic voltammetry were used for the measurement of the HOMO, LUMO, and energy band gaps. The photovoltaic performance of the fabricated DSSCs was measured in different solutions comprising water, alcohol, phenylhydrazine, and dinitrophenylhydazine

Improvement of the performance of purple carrot sensitized solar cells by acidic treatment of FTO glass substrate and TiO₂ film

In this paper, dye sensitized solar cells were prepared using titanium dioxide (TiO₂) and natural dye extracted from purple carrot. The performance of dye sensitized solar cells was significantly improved through the pre- and post-treatments of the fluorinated tin oxide (FTO) glass substrate and the TiO₂ film using hydrochloric (HCl), phosphoric (H₃PO₄), and nitric (HNO₃) acids. The results showed that the pre-treatment of the FTO with H₃PO₄ and the post-treatment of TiO₂ with HNO₃ resulted in improved efficiencies of 130% and 250%, respectively

Dye Sensitized Solar Cells Based on Hydrazonoyl Synthetic Dyes

A group of chemical sensitizers of two hydrazonoyl based derivatives were synthesized. These derivatives contain a good π system for efficient light absorption and oxide sensitization. Precursor structure I was reacted with 2,6-diaminopyridine, 2-aminobenzoic acid, 4-aminobenzoic acid, 2-aminopyridine, 2,6-dinitrophenylhydrazine, and diphenylamine. The other precursor, structure (II), was reacted with 2-aminobenzoic acid, 2-amino-3-methyl, and 2-amino-4-methylpyridine. A total of 9 dyes were prepared and evaluated as sensitizers for dye-sensitized solar cells (DSSCs). Full computational calculations using DFT B3LYP 6-31+G were carried out for evaluation of band edge and band gap energies of all compounds. The absorption spectra of these dyes as well as cyclic voltammetry were used for the measurement of the HOMO, LUMO, and energy band gaps. The photovoltaic performance of the fabricated DSSCs was measured in different solutions comprising water, alcohol, phenylhydrazine, and dinitrophenylhydazine

Informal Cairo: Between Islamist Insurgency & the Neglectful State?

From the late 1980s, Islamist militants established a ‘state within the state’ in the Egyptian capital Cairo, situated in ‘informal’ neighbourhoods developed without official authorization, planning or public services. After government security forces in late 1992 crushed these efforts in the neighbourhood of Munira Gharbiyya, informal Cairo became pathologized in public discourse as ashwa’iyyat (‘random’ or ‘haphazard’ areas), a zone of socio-spatial disorder threatening Egypt as a whole and demanding state intervention. However, this securitizing move did not lead to heavy-handed intervention against informal Cairo more generally. Following the suppression of the militants, the Mubarak government instead returned to long-term patterns of indifference and neglect that had allowed informal neighbourhoods to flourish since the 1960s. In part, the absence of intervention can be explained in terms of resource constraints and risk avoidance. More profoundly, however, it reflects numerous linkages between informal urbanization and the Egyptian state. The ashwa’iyyat are, to a significant degree, both a consequence of an authoritarian political order and embedded in the informal control stratagems used by Egyptian governments to bolster their rule. Informal Cairo should thus not be understood as a disorderly zone of subaltern dissidence. Rather, the Egyptian state is best seen as facing its own oblique reflection

Global Incidence and Risk Factors Associated With Postoperative Urinary Retention Following Elective Inguinal Hernia Repair

Importance Postoperative urinary retention (POUR) is a well-recognized complication of inguinal hernia repair (IHR). A variable incidence of POUR has previously been reported in this context, and contradictory evidence surrounds potential risk factors.Objective To ascertain the incidence of, explore risk factors for, and determine the health service outcomes of POUR following elective IHR.Design, Setting, and Participants The Retention of Urine After Inguinal Hernia Elective Repair (RETAINER I) study, an international, prospective cohort study, recruited participants between March 1 and October 31, 2021. This study was conducted across 209 centers in 32 countries in a consecutive sample of adult patients undergoing elective IHR.Exposure Open or minimally invasive IHR by any surgical technique, under local, neuraxial regional, or general anesthesia.Main Outcomes and Measures The primary outcome was the incidence of POUR following elective IHR. Secondary outcomes were perioperative risk factors, management, clinical consequences, and health service outcomes of POUR. A preoperative International Prostate Symptom Score was measured in male patients.Results In total, 4151 patients (3882 male and 269 female; median [IQR] age, 56 [43-68] years) were studied. Inguinal hernia repair was commenced via an open surgical approach in 82.2% of patients (n = 3414) and minimally invasive surgery in 17.8% (n = 737). The primary form of anesthesia was general in 40.9% of patients (n = 1696), neuraxial regional in 45.8% (n = 1902), and local in 10.7% (n = 446). Postoperative urinary retention occurred in 5.8% of male patients (n = 224), 2.97% of female patients (n = 8), and 9.5% (119 of 1252) of male patients aged 65 years or older. Risk factors for POUR after adjusted analyses included increasing age, anticholinergic medication, history of urinary retention, constipation, out-of-hours surgery, involvement of urinary bladder within the hernia, temporary intraoperative urethral catheterization, and increasing operative duration. Postoperative urinary retention was the primary reason for 27.8% of unplanned day-case surgery admissions (n = 74) and 51.8% of 30-day readmissions (n = 72).Conclusions The findings of this cohort study suggest that 1 in 17 male patients, 1 in 11 male patients aged 65 years or older, and 1 in 34 female patients may develop POUR following IHR. These findings could inform preoperative patient counseling. In addition, awareness of modifiable risk factors may help to identify patients at increased risk of POUR who may benefit from perioperative risk mitigation strategies