Nearby lightning strokes are often considered as a prime source of transient overvoltages in the substations. Lightning overvoltages can cause unreliable operation of power system and power supply interruptions. Calculation of expected lightning overvoltages is necessary to design appropriate protection system. This paper presents the analysis of the lightning overvoltage performance of real 400 kV overhead transmission line and gas insulated substation (GIS), considering various factors, such as lightning stroke locations, peak currents, front rise times, etc. EMTP-RV software was used to model transmission line and substation elements and conduct simulations, while transmission line lightning performance was determined using Sigma Slp software. The expected overvoltages and surge arrester currents are calculated and used to design lightning protection system of the considered substation. Obtained results also indicate the importance of proper modelling of power system elements and lightning strokes.
Fermentation is a crucial process in the production of alcoholic beverages such as spirits, which produces a number of volatile compounds due to the metabolic activities of yeast. These volatile compounds, together with the volatile components of the raw materials and the volatile compounds produced during the distillation and aging process, play a crucial role in determining the final flavor and aroma of spirits. In this manuscript, we provide a comprehensive overview of yeast fermentation and the volatile compounds produced during alcoholic fermentation. We will establish a link between the microbiome and volatile compounds during alcoholic fermentation and describe the various factors that influence volatile compound production, including yeast strain, temperature, pH, and nutrient availability. We will also discuss the effects of these volatile compounds on the sensory properties of spirits and describe the major aroma compounds in these alcoholic beverages.
Process-based models and empirical modelling techniques are frequently used to (i) explore the sensitivity of tree growth to environmental variables, and (ii) predict the future growth of trees and forest stands under climate change scenarios. However, modelling approaches substantially influence predictions of the sensitivity of trees to environmental factors. Here, we used tree-ring width (TRW) data from 1630 beech trees from a network of 70 plots established across European mountains to build empirical predictive growth models using various modelling approaches. In addition, we used 3-PG and Biome-BGCMuSo process-based models to compare growth predictions with derived empirical models. Results revealed similar prediction errors (RMSE) across models ranging between 3.71 and 7.54 cm2 of basal area increment (BAI). The models explained most of the variability in BAI ranging from 54 % to 87 %. Selected explanatory variables (despite being statistically highly significant) and the pattern of the growth sensitivity differed between models substantially. We identified only five factors with the same effect and the same sensitivity pattern in all empirical models: tree DBH, competition index, elevation, Gini index of DBH, and soil silt content. However, the sensitivity to most of the climate variables was low and inconsistent among the empirical models. Both empirical and process-based models suggest that beech in European mountains will, on average, likely experience better growth conditions under both 4.5 and 8.5 RCP scenarios. The process-based models indicated that beech may grow better across European mountains by 1.05 to 1.4 times in warmer conditions. The empirical models identified several drivers of tree growth that are not included in the current process-based models (e.g., different nutrients) but may have a substantial effect on final results, particularly if they are limiting factors. Hence, future development of process-based models may build upon our findings to increase their ability to correctly capture ecosystem dynamics.
Context: Rivaroxaban is an oral direct factor Xa inhibitor reducing the risk of systemic embolism and stroke in patients with nonvalvular atrial fibrillation. Aims: The primary objective was to evaluate the effectiveness of rivaroxaban therapy in reducing the risk of systemic embolism and stroke in patients with nonvalvular atrial fibrillation, whereas secondary objectives were to monitor therapy safety and the patients' adherence to treatment. Settings and Design: The prospective, postmarketing clinical trial was conducted on patients with nonvalvular atrial fibrillation with one or more risk factors, such as congestive heart failure, hypertension, and diabetes mellitus, who suffered a stroke or a transient ischemic attack. Subjects and Methods: At the baseline visit, the CHA2DS2 score was determined, and therapy was introduced. At three control visits (1, 3, and 6 months after baseline), systemic embolism, stroke, bruises, or bleeding occurrences were recorded. Furthemore, adverse events were monitored, and the Morisky score (MMAS-8) for treatment compliance was determined. Results were compared to previous studies. Results: The study included 471 patients. The incidence rate in events per 100 patient-years (95% confidence interval) was 2.6 (0.1–5.1) for systemic embolism and 4.3 (1.6–7.0) for stroke. The most common form of bleeding during rivaroxaban therapy was epistaxis. Adverse events were reported in 12 (2.7%) patients. Therapy adherence was in the range of medium adherence for the entire study period, with the average score decreasing significantly from the 1st to 6th months (P < 0.001). Conclusions: Rivaroxaban showed good efficacy and safety in reducing the risk of systemic embolism and stroke in patients with nonvalvular atrial fibrillation including patients with comorbidities.
In this paper, the possible synergistic effects of fly wood biomass ash (WBA) and recycled tire polymer fibres (RTPF) on long-term autogenous shrinkage and drying shrinkage in mortar were investigated, and the pore structures of mortar specimens with WBA and RTPF were determined. The results showed that the use of RTPF and WBA has an effect on the pore structure of mortars and thus on the results of autogenous shrinkage. When WBA and RTPF were used, the autogenous shrinkage tended to decrease; however, this was not the case for the drying shrinkage. The greatest reduction in autogenous shrinkage was achieved by the addition of WBA and RTPF; autogenous shrinkage was reduced by 62 % after 90 days compared with the reference mixture.
COVID-19 vaccines have been widely used to reduce the incidence and disease severity of COVID-19. Questions have lately been raised about the possibility of an association between COVID-19 vaccines and myocarditis, an inflammatory condition affecting the myocardium, or the middle layer of the heart. Myocarditis can be caused by infections, immune reactions, or toxic exposure. The incidence rate of myocarditis and pericarditis was calculated to be 5.98 instances per million COVID-19 vaccine doses delivered, which is less than half of the incidences after SARS-CoV-2 infection. Myocarditis rates in people aged 12 to 39 years are around 12.6 cases per million doses following the second dose of mRNA vaccination. Adolescent men are more likely than women to develop myocarditis after receiving mRNA vaccines. The objectives of this systematic review and meta-analysis are to find out how often myocarditis occurs after receiving the COVID-19 vaccine, as well as the risk factors and clinical repercussions of this condition. Nevertheless, the causal relationship between vaccination and myocarditis has been difficult to establish, and further research is required. It is also essential to distinguish between suggested cases of myocarditis and those confirmed by endomyocardial biopsy.
Graphene has a large optical nonlinearity and supports electrically-tunable and long-lived plasmons. We present an experimental study of harmonic generation in graphene heterostructures, which enhance the nonlinearity and allow plasmons to mediate the non-linear response.
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