Microstructural Evolution of AA5154 Layers Intermixed with Mo Powder during Electron Beam Wire-Feed Additive Manufacturing (EBAM)

AA5154 aluminum alloy wall was built using EBAM where the wall’s top layers were alloyed by depositing and then remelting a Mo powder-bed with simultaneous transfer of aluminum alloy from the AA5154 wire. The powder-beds with different concentrations of Mo such as 0.3, 0.6, 0.9 and 1.2 g/layer were used to obtain composite AA5154/Mo samples. All samples were characterized by inhomogeneous structures composed of as-deposited AA5154 matrix with coarse unreacted Mo articles and intermetallic compounds (IMC) such as Al12Mo, Al5Mo, Al8Mo3, Al18Mg3Mo2 which formed in the vicinity of these Mo particles. The IMC content increased with the Mo powder-bed concentrations. The AA5154 matrix grains away from the Mo particles contained Al-Fe grain boundary precipitates. Mo-rich regions in the 0.3, 0.6, 0.9 and 1.2 g/layer Mo samples had maximum microhardness at the level of 2300, 2600, 11,500 and 9000 GPa, respectively. Sliding pin-on-steel disk test showed that wear of A5154/Mo composite reduced as compared to that of as-deposited AA5154 due to composite structure, higher microhardness as a well as tribooxidation of Al/Mo IMCs and generation of mechanically mixed layers containing low shear strength Mo8O23 and Al2(MoO4)3 oxides.

O-199 Proof of concept: implantation window must be wider than proposed. Report of seven twins after asynchronous double embryo transfer

Study question Can simultaneous transfer of two embryos that were cryopreserved at different stages (D3 and Blastocyst) be appropriate to enhance success in women with more than three failed embryo transfers? Summary answer Double asynchronous embryo transfer offered excellent results in RIF. Unexpectedly high twin rate suggests that embryo-endometrium synchrony is overemphasized. Implantation window must be wider. What is known already Transcriptomic signature of the endometrium has been investigated in the last few years trying to understand the best moment for embryo implantation. Nevertheless, the optimal period has not been well established yet in humans. Simultaneous transfer of two human embryos at different developmental stages (D3 and Blastocyst) on Day 4 was proposed to help couples who have had RIF. Study design, size, duration Observational case-control study. From April 2016 to January 2021, we offered double asynchronous embryo transfer only after Recurrent Implantation Failure (RIF). Two requirements were necessary: 1) Double embryo transfer was acceptable by the couple due to poor reproductive outcome. 2) Availability of two embryos cryopreserved at different stage (D3 and Blastocyst). Results were compared with good prognosis patients (all patients under 35 years in that period who had elected to transfer two day 3 cryopreserved embryos). Participants/materials, setting, methods Forty-five patients accepted to participate in the study. Results were compared with all patients (237) under 35 years where two D3 thawed embryos were transferred. All cases received same protocol (oral estradiol 6mg/d or vaginal estradiol 4mg/d until ultrasound showed endometrial growth) LH, P4 and E2 were monitored in all patients to detect spontaneous LH surge. All cases received transvaginal micronized progesterone 800 mg/d. Embryo transfers were ultrasound guided and Wallace Embryosure catheter was employed. Main results and the role of chance Limitations, reasons for caution Multiple pregnancy rate was unacceptably high. Therefore, it should not be suggested for good prognosis couples where single embryo transfer is clearly advidsed. Our main limitation was the combination of D3 embryos with blastocysts. The retrospective design make the results to be considered as a proof of concept. Wider implications of the findings Double asynchronic embryo transfer can offer new insights in the understanding of human implantation. The concept of implantation window is clearly challenged. Aiming to the center of the window is fine, but we still dońt know how wide is that center. Trial registration number not applicable

FAMILY AS AN OBJECT IN THE FORMATION OF A NEW GENDER ORDER

The article presents the main characteristics inherent in the Russian family as a small social group in line with a new gender order. In the 21st century one may see the new traits, characteristics and functions of the gender and gender relations, which is reflected in the emergence of a new gender order, which sociologists and feminologists have started talking about. The concept of a gender order is briefly defined and a historical retrospective of its emergence is given. The author marks three main subjects in which the changes taking place in the Russian family in recent decades are analyzed. First of all, it is the variability of family scenarios, which consists in different gender compositions of families (if we take the example of a country with officially permitted homosexual marriages); in matters of the childbirth, divorce, housekeeping practices, etc. Secondly, it is a change in gender roles, which is manifested in the growth of economic activity of women, their growing financial independence within the family, with the simultaneous transfer of the household responsibilities to a man. That plot leads to a third feature: changes in the family lifestyle what is most clearly evidenced by the strengthened educational function of the father. The family simultaneously reflects changes in a gender order and generates them, which speaks in favor of the relevance of the topic being studied.

Comparing Molecular Mechanisms in Solar NH3 Production and Relations with CO2 Reduction

Molecular mechanisms for N2 fixation (solar NH3) and CO2 conversion to C2+ products in enzymatic conversion (nitrogenase), electrocatalysis, metal complexes and plasma catalysis are analyzed and compared. It is evidenced that differently from what is present in thermal and plasma catalysis, the electrocatalytic path requires not only the direct coordination and hydrogenation of undissociated N2 molecules, but it is necessary to realize features present in the nitrogenase mechanism. There is the need for (i) a multi-electron and -proton simultaneous transfer, not as sequential steps, (ii) forming bridging metal hydride species, (iii) generating intermediates stabilized by bridging multiple metal atoms and (iv) the capability of the same sites to be effective both in N2 fixation and in COx reduction to C2+ products. Only iron oxide/hydroxide stabilized at defective sites of nanocarbons was found to have these features. This comparison of the molecular mechanisms in solar NH3 production and CO2 reduction is proposed to be a source of inspiration to develop the next generation electrocatalysts to address the challenging transition to future sustainable energy and chemistry beyond fossil fuels.

Comparing Molecular Mechanisms in Solar NH3 Production and Relations with CO2 Reduction

Molecular mechanisms for N2 fixation (solar NH3) and CO2 conversion to C2+ products in enzymatic conversion (Nitrogenase), electrocatalysis, metal-complexes and plasma-catalysis are analysed and compared. It is evidenced that differently from what present in thermal and plasma-catalysis, the electrocatalysis path requires not only the direct coordination and hydrogenation of undissociated N2 molecule, but to realize a series of features present in the Nitrogenase mechanism. There is the need of i) a multi-electron and -proton simultaneous transfer, not as sequential steps, ii) forming bridging metal hydride species, iii) generate intermediates stabilized by bridging multiple metal atoms, iv) have the capability of the same sites to be effective both in N2 fixation and in COx reduction to C2+ products. Only iron oxide/hydroxide stabilized at defective sites of nanocarbons was found to have these features. This comparison of the molecular mechanisms in solar NH3 production and relations with CO2 reduction is proposed to be a source of inspiration to develop the next generation electrocatalysts to address the challenging transition to a future sustainable energy and chemistry beyond fossil fuels.

Understanding the mass, momentum, and energy transfer in the frozen soil with three levels of model complexities

Frozen ground covers a vast area of the Earth's surface and it has important ecohydrological implications for cold regions under changing climate. However, it is challenging to characterize the simultaneous transfer of mass and energy in frozen soils. Within the modeling framework of Simultaneous Transfer of Mass, Momentum, and Energy in Unsaturated Soil (STEMMUS), the complexity of the soil heat and mass transfer model varies from the basic coupled model (termed BCM) to the advanced coupled heat and mass transfer model (ACM), and, furthermore, to the explicit consideration of airflow (ACM–AIR). The impact of different model complexities on understanding the mass, momentum, and energy transfer in frozen soil was investigated. The model performance in simulating water and heat transfer and surface latent heat flux was evaluated over a typical Tibetan plateau meadow site. Results indicate that the ACM considerably improved the simulation of soil moisture, temperature, and latent heat flux. The analysis of the heat budget reveals that the improvement of soil temperature simulations by ACM is attributed to its physical consideration of vapor flow and the thermal effect on water flow, with the former mainly functioning above the evaporative front and the latter dominating below the evaporative front. The contribution of airflow-induced water and heat transport (driven by the air pressure gradient) to the total mass and energy fluxes is negligible. Nevertheless, given the explicit consideration of airflow, vapor flow and its effects on heat transfer were enhanced during the freezing–thawing transition period.