Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years

Enhanced performance of dye sensitized solar cells utilizing platinum electrodeposit counter electrodes

Enhanced performance was observed for dye-sensitized solar cells (DSSCs) utilizing counter electrodes based on Pt electrodeposits compared to counter electrodes based on sputtered Pt. Scanning electron microscopy of Pt electrodeposits revealed that the use of an initial cathodic overpotential pulse followed by steady electrodeposition at a mild cathodic potential yielded ∼40nm particles, compared to ∼600nm particles when no such pulse was used. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) of electrode materials suggested that Pt electrodeposits would give enhanced performance as DSSC counter electrodes compared to sputtered Pt, and this was confirmed by device testing. EIS characterization of DSSCs under illumination revealed that Pt electrodeposit counter electrodes were found to be more catalytically stable compared to sputtered Pt. The best counter electrode was based on Pt electrodeposited using an initial cathodic overpotential pulse and demonstrated charge-transfer resistance [RCT(Pt)]values of 0.6 and 0.7Ωcm2 within a symmetrical Pt/I−3/I−/Pt cell and within a DSSC, respectively

Optimal Selection of the Diesel Generators Supplying a Ship Electric Power System

It is very common for ships to have electric power systems comprised of generators of the same type. This uniformity allows for easier and lower-cost maintenance. The classic way to select these generators is primarily by power and secondarily by dimensions and acquisition cost. In this paper, a more comprehensive way to select them, using improved cost indicators, is proposed. These take into account many factors that have a significant impact in the life-cycle cost of the equipment. A realistic and detailed profile of the ship’s electric load spanning a full year of her operation is also developed to allow for a solution that is tailor-made to a specific case. The method used is highly iterative. All combinations of genset quantities and capacities are individually considered to populate a power plant, taking into account the existing redundancy requirements. For each of these and for every time interval in the load profile, the engine consumption is Lagrange-optimized to determine the most efficient combination to run the generators and the resulting cost. The operating cost throughout the year is thus derived. In this way, the method can lead to optimal results as large data sets regarding ship operation and her power system’s technical characteristics can be utilized. This intense calculation process is greatly accelerated using memorization techniques. The reliability cost of the current power plant is also considered along with other cost factors, such as flat annual cost, maintenance, and personnel. The acquisition and installation cost are also included, after being distributed in annuities for various durations and interest rates. The results provide valuable insight into the total cost from every aspect and present the optimum generator selection for minimal expenditure and maximum return of investment. This methodology may be used to enhance the current power-plant design processes and provide investors with more feasible alternatives, as it takes into consideration a multitude of technical and operational characteristics of the examined ship power system

Charge transport in dye-sensitized solar cells based on flame-made TiO2 nanoparticles

The fundamental understanding on charge-transport properties of flame-synthesized TiO2 in dye-sensitized solar cells (DSSCs) is established in this work. By employing a one-step flame spray pyrolysis (FSP), predominantly anatase TiO2 nanoparticles with average nanoparticle sizes between 11 and 36 nm were achieved by varying the rate of combustion enthalpy (through varying liquid precursor feed flow rates) and using either an “openflame” or “enclosed-flame” configuration. Electron diffusion coefficient (D), electron lifetime (τ ), open circuit voltage (Voc ), and capacitance (C) measurements carried out on FSP TiO2 -based DSSCs demonstrated that interband charge trap density decreased with increase in particle size. Compared to earlier studies, interband charge trap density could be controlled more independently of particle size. Under one-sun conditions, relatively high Voc was measured with large particle size due to the lowering of interband charge trap density. This was true despite the associated shorter τ . Comparisons with commercial benchmark Nanoxide-T and Degussa P25 TiO2 were also carried out. The results from the current study have significant implications on the design of TiO2 nanoparticles by flame aerosol techniques, for DSSCs as well as other photoelectrochemical applications. Index Terms—Electron diffusion coefficien

Bubble Detection on the Cathode and Anode of a High-Performing Capillary-Fed Water Electrolysis Cell

The cathode and anode of a ‘bubble-free’ ‘capillary-fed’ water electrolysis cell that was previously reported to consume only 40.4 kWh kg-1 hydrogen under standard commercial operating conditions, have been separately investigated for the incidence of gas bubble formation during operation. Adaptions of a voltage fluctuation and an acoustic emission technique were applied in combination, to detect and analyze bubble formation at current densities up to 1 A cm-2. The two techniques produced very similar results, showing little bubble formation up to 0.17-0.20 A cm-2. Thereafter, bubbles were formed predominantly at the cathode up to ~0.6 A cm2. At higher current densities, the cathode and anode produced bubbles at similar rates, that were substantially lower than in conventional, ‘bubbled’ electrolysis cells. In the course of this work, the previously reported high electrochemical performance of the capillary-fed cell was independently confirmed

Remarkable synergistic effects in a mixed porphyrin dye-sensitized TiO2 film

A remarkable 300% efficiency enhancement driven by a matching increase in the short circuit current was observed in a mixed porphyrin dye-sensitized solar cell constructed from two dyes in a 3:1 ratio. Absorbed photon-to-current conversion efficiency measurements indicate an improved charge injection yield for both dyes in the mixture. Several possible origins for the observed performance enhancement are discussed