First‐principles Assessment of the Role of Water in the Reduction Half Cycle of Low‐Temperature NH3‐SCR over Cu‐CHA

Dispersion corrected density functional theory calculations show that the presence of H2O in the Reduction Half-Cycle (RHC) of NH3-SCR affects the free energy of the kinetically-relevant transition state (TS) leading to a reduction in the rate and activation energy with respect to dry conditions. In particular, H2O enthalpically stabilizes the kinetically-relevant TS by 20 kJ mol(-1) with respect to the dry counterpart. Such enthalpic stabilization vanishes when van der Waals (vdW) interactions are excluded from the calculations, thus showing the preeminent role of non-specific dispersion forces in the reduction of the activation enthalpy. At the same time, the enthalpic stabilization is more than compensated by the additional entropy losses of the TS brought forth by the presence of H2O in the CHA cage. Calculated enthalpy and entropy changes with respect to the dry case agree quantitatively with the experimental measurements and reflect the modified reacting environment in the presence of H2O. As a result, this study provides theoretical underpinnings on the mechanistic role of H2O in the RHC and, on a more general basis, highlights the importance of the molecular scale description of the reaction environment in voids of molecular dimensions

The Effect of CH4 on NH3-SCR Over Metal-Promoted Zeolite Catalysts for Lean-Burn Natural Gas Vehicles

We present a systematic investigation of the deNO(x) activity of two commercial metal exchanged zeolite NH3-SCR catalysts, a Cu-SAPO and a Fe-BEA, in view of their application to the exhaust after-treatment systems of lean-burn natural gas vehicles. The catalytic activity data collected under realistic operating conditions, representative of the after-treatment system of lean-burn vehicles, were compared to those obtained adding methane to the gas feed stream in order to assess the impact of this hydrocarbon, which is usually emitted from natural gas engines, on the NH3-SCR catalytic chemistry. Our results indicate a negligible impact of methane on the SCR activity at all conditions, but in the presence of a large excess of NO2 at T>400 degrees C due to methane oxidation by NO2. The data collected over the two individual metal-promoted zeolites were also compared with those obtained combining both catalysts in sequential arrangements, in order to take advantage of their complementary high activities in different temperature ranges. The Fe-zeolite+Cu-zeolite sequence outperformed the two individual components in terms of both overall deNOx efficiency and N2O selectivity, and was equally insensitive to methane

Pendidikan Kesehatan Yang Service Excellent Tentang Pain Relief Pada Saat Persalinan Di Desa Bangun Rejo Kecamatan Morawa Deli Serdang Tahun 2023

Labor pain is a physiological response that occurs due to an increase in catecholamines that interfere with uterine contractions. Labor pain can be overcome with various alternatives. However, the lack of health promotion related to pain relief strategies causes the majority of pregnant women to lack information literacy on how to deal with pain relief during childbirth. This community service activity was carried out in conjunction with the KKN midwifery undergraduate students at STIKes Mitra Husada Medan in Desa Bangun Rejo, Tanjung Morawa District. The main activity program is to provide education to pregnant women who will give birth with counseling about pain relief strategies during childbirth. This community service method adopts action research steps. Evaluating the program using a questionnaire. The results of the community service which was attended by 10 third trimester pregnant women, it turned out that this activity received a good and positive response from pregnant women. Furthermore, the results of the evaluation of this counseling were obtained, 60% of pregnant women could understand and explain the definition of pain relief strategies and the goals of pain relief strategies, 70% of pregnant women could understand and explain the handling of pain relief strategies. It is hoped that village midwives can also provide health education to birth attendants about pain relief strategies that can be implemented. &nbsp

Dual Mode NOx Sensor: Measuring Both the Accumulated Amount and Instantaneous Level at Low Concentrations

The accumulating-type (or integrating-type) NOx sensor principle offers two operation modes to measure low levels of NOx: The direct signal gives the total amount dosed over a time interval and its derivative the instantaneous concentration. With a linear sensor response, no baseline drift, and both response times and recovery times in the range of the gas exchange time of the test bench (5 to 7 s), the integrating sensor is well suited to reliably detect low levels of NOx. Experimental results are presented demonstrating the sensor’s integrating properties for the total amount detection and its sensitivity to both NO and to NO2. We also show the correlation between the derivative of the sensor signal and the known gas concentration. The long-term detection of NOx in the sub-ppm range (e.g., for air quality measurements) is discussed. Additionally, a self-adaption of the measurement range taking advantage of the temperature dependency of the sensitivity is addressed

La mort des Sirènes dans la littérature grecque de l’époque classique

Cette contribution porte sur la tradition posthomérique de la mort des Sirènes, après le passage du bateau d’Ulysse, parce qu’elles n’ont pas été capables de le charmer. La représentation de leur suicide sur un stamnos du Ve siècle avant J.-C. (Londres BM 1943.11-3.31) montre que cette légende était assez connue dans l’Antiquité ; elle peut donc aider dans l’interprétation de quelques passages littéraires très débattus où les Sirènes se trouvent dans l’Hadès (Eur. Hel 168-78 ; Soph. fr. 861 Radt ; Plat. Crat 403d). Plutôt que d’expliquer ces textes avec la référence à la figure de la « Sirène funéraire », une décoration pour les tombes assez commune, on pourrait les comparer avec la tradition mythique connue à l’époque sur ce sujet.This paper deals with the post-Homeric tradition on the death of the Sirens after the passage of Odysseus’ship, due to their failure in charming him. The representation of their suicide on a stamnos dating back to the 5th century (London 1943.11-3.31) shows that this legend was quite known in Antiquity and so it could help in the understanding of three much debated literary occurrences according to which the Sirens dwell in the Hades (Eur. Hel 168-78; Soph. fr. 861 Radt; Plat. Crat 403d). Rather than explaining these texts with the reference to the “funerary Siren”, a quite common decoration for tombs, it could be possible to compare them with a mythical tradition on this topic which was popular at that time

Auctoritas Homerica? Homer and the Greek culture of the classical period.

Questo lavoro ha per oggetto il trattamento degli episodi del ciclo troiano presenti, da un lato, nei poemi omerici, e, dall’altro, nella letteratura e nell’arte figurativa di età classica. L’obiettivo è quello di stabilire quale fosse l’autorità dell’Iliade e dell’Odissea nel V e IV secolo per gli autori e gli artisti che si trovavano a riprendere i medesimi argomenti. Attraverso un esame attento dei casi in cui si riscontrano differenze tra la riproposizione di età classica e la versione dei poemi omerici, è emerso, da un lato, che le differenze rispetto a Omero non costituiscono casi sporadici, ma sono documentabili in numerosi testi e in numerose rappresentazioni. Dall’altro, che, soppesando prudentemente le diverse possibilità, ne risulta un quadro diversificato, in cui l’influenza della versione omerica può essere considerata possibile o da escludere. Il valore canonico che è attribuito ai poemi omerici in età successive non è quindi rintracciabile già nell’età classica: la versione omerica non era che una tra le tante a cui era possibile ispirarsi nella trattazione di un episodio del ciclo troiano.This research focuses on the handling of the episodes belonging to the Trojan cycle which appear both in the Homeric epics and in the literature and iconography of the classical period. It aims at showing if an ipothetic authority of the Iliad and the Odyssey in the 5th and 4th century was determining for artists and authors who dealt with the same subjects. Through a careful analysis of the differences between the version which appears in the classical age and in the Homeric one, it is possible to state that these differences are not sporadic, but they can be found in a number of texts and representations. Moreover, taking into account every possible explanation, the resulting picture is a variegated one, made up of cases where the influence of the Homeric version may be considered as possible and cases where it has to be excluded. In conclusion, the canonical value which is attributed to the poems in later times can’t be detected in the classical age: the Homeric version is just one out of many legends to which it was possible to make reference while dealing with an episode of the Trojan cycle

A Trypsin Inhibitor from Moringa oleifera Flowers Modulates the Immune Response In Vitro of Trypanosoma cruzi-Infected Human Cells

Trypanosoma cruzi causes the lethal Chagas disease, which is endemic in Latin America. Flowers of Moringa oleifera (Moringaceae) express a trypsin inhibitor (MoFTI) whose toxicity to T. cruzi trypomastigotes was previously reported. Here, we studied the effects of MoFTI on the viability of human peripheral blood mononuclear cells (PBMCs) as well as on the production of cytokines and nitric oxide (NO) by T. cruzi-infected PBMCs. Incubation with MoFTI (trypsin inhibitory activity: 62 U/mg) led to lysis of trypomastigotes (LC50 of 43.5 µg/mL) but did not affect the viability of PBMCs when tested at concentrations up to 500 µg/mL. A selectivity index > 11.48 was determined. When T. cruzi-infected PBMCs were treated with MoFTI (43.5 or 87.0 µg/mL), the release of the pro-inflammatory cytokine TNF-α and INF-γ, as well as of NO, was stimulated. The release of the anti-inflammatory cytokine IL-10 also increased. In conclusion, the toxicity to T. cruzi and the production of IL-10 by infected PBMCs treated with MoFTI suggest that this molecule may be able to control parasitemia while regulating the inflammation, preventing the progress of Chagas disease. The data reported here stimulate future investigations concerning the in vivo effects of MoFTI on immune response in Chagas disease