Impact of the electrode proximity on the streamer breakdown and development of pulsed dielectric barrier discharges

The impact of the electrode proximity on the streamer breakdown and development of pulsed-driven dielectric barrier discharges (DBDs) in a single-filament arrangement has been investigated in a gas mixture of 0.1 vol% O2 in N2 at 0.6 bar and 1.0 bar. The gap distance was varied from 0.5 mm to 1.5 mm, and the applied voltage was adapted correspondingly to create comparable breakdown conditions in the gap. The development of the DBDs was recorded by an iCCD and a streak camera system, while fast electrical measurements provided insight into discharge characteristics such as the transferred charge and consumed energy. The results demonstrate that breakdown in a smaller gap is characterised by a slower streamer propagation but a significantly higher acceleration. It can therefore be concluded that the proximity of the cathode has a strong impact on the characteristics of the streamer breakdown. However, after the streamer has crossed the gap, the discharge structure in front of the anode was found to be the same independent of the actual gap distance

The Power of Education to Reduce the Carbon Footprint of Volatile Anesthetics in Clinical Practice

BACKGROUND: Due to their chemical nature as fluorinated hydrocarbon compounds, volatile anesthetics are highly potent greenhouse gases, with desflurane having by far the largest CO2-equivalent (CO2e) footprint. In everyday clinical practice, the CO2e footprint can easily be reduced through the increased use of propofol or sevoflurane as well as low- and minimal-flow techniques or through the more frequent use of regional anesthesia techniques. We wanted to assess to what extent educational measures on sustainability aspects of the use of volatile anesthetics had an impact on daily practice in anesthesiology departments and to what extent this influenced the hospital's CO2e emissions. METHODS: We conducted an observational data analysis of the consumption of anesthetics (sevoflurane, desflurane, isoflurane, and propofol) at all 3 clinical Charité campuses in the period from 2015 to 2023. The CO2e emissions were calculated for sevoflurane, desflurane, and isoflurane. External and internal (top-down or bottom-up) educational measures focusing on sustainability in anesthesia took place from September 2018 on. Shifts in CO2e emissions related to the educational measures are shown in a run chart. The number of surgeries, surgery duration, and purchasing costs were included in the analysis. RESULTS: CO2e emissions of volatile anesthetics were reduced by 90.3% from the baseline epoch (years 2015-2017) before educational interventions took place to 2023: CO2e 1470 tons (mean 2015-2017), to 191 tons (2022) to 142 tons (2023). This change was brought about by the phasing out of desflurane and the use of propofol or sevoflurane and regional anesthesia where appropriate. The fastest and most sustainable changes were seen after internal top-down measures. The total cost of anesthetics also fell over the period under review (from €541,102/$594,238 in 2015 to €281,646/$309,303 in 2023). CONCLUSIONS: Educational measures for anesthesiologists about the climate-damaging effects of volatile anesthetics - especially desflurane - can significantly reduce CO2e emissions in anesthesia clinics. On the positive side, these measures have also reduced the annual costs for anesthetics.</p

Essential Biodiversity Variables

There is an urgent need to develop a global system for biodiversity observations, with harmonized and regular measurements of a set of Essential Biodiversity Variables covering the different dimensions of biodiversity change, to provide scientists, managers and policy-makers with accurate and timely information.JRC.H.1 - Water Resource

Local infiltration analgesia versus peripheral nerve block anaesthesia in total knee arthroplasty: a pharmaco-economic comparison

Background: A superior analgesic method in perioperative pain-management of patients receiving total knee arthroplasty is the subject of controversial debate. Although higher cost-efficiency is claimed for the local infiltration analgesia (LIA), there is a lack of data on its costs compared to peripheral nerve block anaesthesia (PNBA). The goal of this study was to investigate the differences in immediate perioperative costs between the LIA and PNBA in treatment of patients receiving total knee arthroplasty. Methods: The comparison was conducted based on a randomized controlled clinical trial examining 40 patients with elective, primary total knee arthroplasty (TKA, 20 patients with LIA and 20 patients with PNBA). The analysis included surgical case costs, anaesthesiological case costs, material, costs of postoperative opioid requirements and catheter review visits for patients receiving PNBA. Results: The overall mean costs for the LIA-group were 4328.72(sic) and 4368.12(sic) for the PNBA (p = 0.851). While there was no statistically significant difference in surgical case costs, the anaesthesiological costs were lower with the LIA procedure (1370.26(sic) vs. 1542.45(sic), p = 0.048). Material costs in the LIA group were 4.18(sic)/patient and 94.64(sic)/patient with the PNBA. Costs for postoperative opioid requirements showed no statistically significant difference between the two procedures. Conclusions: There is no relevant difference in immediate perioperative costs between LIA and PNBA. Shorter induction times lead to lower anaesthesiological case costs with the LIA. Overall economic aspects seem to play a less important role for determining an adequate procedure for perioperative pain management

The only African wild tobacco, Nicotiana africana: Alkaloid content and the effect of herbivory

Herbivory in some Nicotiana species is known to induce alkaloid production. This study examined herbivore-induced defenses in the nornicotine-rich African tobacco N. africana, the only Nicotiana species indigenous to Africa. We tested the predictions that: 1) N. africana will have high constitutive levels of leaf, flower and nectar alkaloids; 2) leaf herbivory by the African bollworm Helicoverpa armigera will induce increased alkaloid levels in leaves, flowers and nectar; and 3) increased alkaloid concentrations in herbivore-damaged plants will negatively affect larval growth. We grew N. africana in large pots in a greenhouse and exposed flowering plants to densities of one, three and six fourth-instar larvae of H. armigera, for four days. Leaves, flowers and nectar were analyzed for nicotine, nornicotine and anabasine. The principal leaf alkaloid was nornicotine (mean: 28 µg/g dry mass) followed by anabasine (4.9 µg/g) and nicotine (0.6 µg/g). Nornicotine was found in low quantities in the flowers, but no nicotine or anabasine were recorded. The nectar contained none of the alkaloids measured. Larval growth was reduced when leaves of flowering plants were exposed to six larvae. As predicted by the optimal defense theory, herbivory had a localized effect and caused an increase in nornicotine concentrations in both undamaged top leaves of herbivore damaged plants and herbivore damaged leaves exposed to one and three larvae. The nicotine concentration increased in damaged compared to undamaged middle leaves. The nornicotine concentration was lower in damaged leaves of plants exposed to six compared to three larvae, suggesting that N. africana rather invests in new growth as opposed to protecting older leaves under severe attack. The results indicate that the nornicotine-rich N. africana will be unattractive to herbivores and more so when damaged, but that potential pollinators will be unaffected because the nectar remains alkaloid-free even after herbivory

Converse Magnetoelectric Composite Resonator for Sensing Small Magnetic Fields

Magnetoelectric (ME) thin film composites consisting of sputtered piezoelectric (PE) and magnetostrictive (MS) layers enable for measurements of magnetic fields passively, i.e. an AC magnetic field directly generates an ME voltage by mechanical coupling of the MS deformation to the PE phase. In order to achieve high field sensitivities a magnetic bias field is necessary to operate at the maximum piezomagnetic coefficient of the MS phase, harnessing mechanical resonances further enhances this direct ME effect size. Despite being able to detect very small AC field amplitudes, exploiting mechanical resonances directly, implies a limitation to available signal bandwidth along with the inherent inability to detect DC or very low frequency magnetic fields. The presented work demonstrates converse ME modulation of thin film Si cantilever composites of mesoscopic dimensions (25 mm × 2.45 mm × 0.35 mm), employing piezoelectric AlN and magnetostrictive FeCoSiB films of 2 µm thickness each. A high frequency mechanical resonance at about 515 kHz leads to strong induced voltages in a surrounding pickup coil with matched self-resonance, leading to field sensitivities up to 64 kV/T. A DC limit of detection of 210 pT/Hz1/2 as well as about 70 pT/Hz1/2 at 10 Hz, without the need for a magnetic bias field, pave the way towards biomagnetic applications

Low-cost,stand-off, 2D+3D face imaging for biometric identification using Fourier transform profilometry –Update

Lockheed Martin Coherent Technologies is developing laser-based technologies for stand-off 2D+3D face imaging for biometric identification. Among other potential industrial, commercial, and governmental users, the Department of Homeland Security (DHS) and the Department of Defense (DoD) desire the ability to capture biometric data from minimally cooperative subjects with a minimally invasive system at stand-off distances. The initial applications are fixed installations for relatively large volume access points such as security check points and transportation gateways for which minimal cooperation, stand-off operation, and real-time operation are desired so that the biometric identification process will have little impact on traffic flow. Last year we presented a paper on the development and testing of a 2D+3D face imager breadboard based on th

Scene Segmentation Driven by Deep Learning and Surface Fitting

This paper proposes a joint color and depth segmentation scheme exploiting together geometrical clues and a learning stage. The approach starts from an initial over-segmentation based on spectral clustering. The input data is also fed to a Convolutional Neural Network (CNN) thus producing a per-pixel descriptor vector for each scene sample. An iterative merging procedure is then used to recombine the segments into the regions corresponding to the various objects and surfaces. The proposed algorithm starts by considering all the adjacent segments and computing a similarity metric according to the CNN features. The couples of segments with higher similarity are considered for merging. Finally the algorithm uses a NURBS surface fitting scheme on the segments in order to understand if the selected couples correspond to a single surface. The comparison with state-of-the-art methods shows how the proposed method provides an accurate and reliable scene segmentation

Product innovation and population dynamics in the German insurance market

Empirical research in organizational ecology has mainly focused on analyzing founding and mortality rates using life history data of the organizations. We try to extend this approach in our study in a number of ways. In contrast to most empirical studies in organizational ecology, we chose a population of service organizations, in particular the German insurance companies, the development dynamics of which are rather obvious in the innovative activities of existing organizations than in founding activities. We further discuss the points of contact between the organizational ecology approach and the theory of industry life cycles and extend the analysis to the relationship between innovative activities and population dynamics. The study examines the effects of population density, former events, and organizational size and age structure in the population of property & casualty insurance companies on the number of product innovations generated. We will further develop a concept for an insurance specific industry life cycle with a non-typical maturation and degeneration phase