Water aeration researches using fine air bubble generators

The paper presents experimental researches able to demonstrate that the aeration installations with mobile fine bubble generators are more efficient than the classic ones with fixed, fine bubble generators. The paper develops water aeration researches by introducing two types of fine air bubble generators: I. Fixed fine air bubble generators, which generate Ø <1 mm bubbles; II. Mobile fine air bubble generators that move in the volume of water subject to aeration. The theoretical and experimental results are presented for the two versions. According to experimental data, aeration with mobile FBG is more efficient in terms of oxygen transfer from atmospheric air to a stationary water mass.

Best practice of using air-bubble curtains as part of complex fish protection structures

Приведены результаты исследований работы комплексных рыбозащитных сооружений с использованием воздушно-пузырьковых завес. Дано описание механизма работы комплексных рыбозащитных сооружений и принципа работы воздушно-пузырьковой завесы. На основе гидравлического расчета разработана методика проектирования и применения воздушно-пузырьковой завесы в составе комплексных рыбозащитных сооружений. Приведены результаты исследований по оценке функциональной эффективности построенных комплексных рыбозащитных сооружений. Комплексные рыбозащитные сооружения, имеющие в своем составе запани и воздушно-пузырьковые завесы и работающие в эрлифтном режиме, достаточно эффективно защищают молодь рыб. При правильно подобранных параметрах работы оборудования и выбранном створе размещения сооружений, с учетом гидравлических и технических особенностей водозабора, их эффективность гарантированно превышает нормативные значения. The results of studying the operation of complex fish protection structures with the use of air-bubble curtains are presented. A description of the operating mechanism of complex fish protection structures and the principle of operation of the air-bubble curtain is given. On the basis of a hydraulic calculation, a method for designing and using an air-bubble curtain as part of complex fish protection structures has been developed. The results of estimating the functional efficiency of the built complex fish protection structures are presented. The complex fish protection structures that include debris deflectors and air-bubble curtains and operate in an air-lift mode, effectively protect fish fry. Provided the operating parameters of the equipment and the selected alignment of the structures with account of the hydraulic and technical features of the water intake have been correctly chosen, their efficiency is guaranteed to exceed the standard values.

The effect of air bubble position on ART outcome in frozen-thawed blastocyst transfer

Background So far, only few literatures have studied the relationship between blastocyst transfer position and ART outcomes, and the conclusions are still controversial. Our study is to evaluate the effect of air bubble position on ART outcome and to find the optimal embryo transfer position in frozen-thawed blastocyst transfer. Methods This study included a retrospective cohort analysis of 399 frozen-thawed single blastocyst transfers ultrasound-guided performed between June 1, 2017 and November 30, 2020. All of the women scheduled for frozen-thawed single blastocyst transfers ultrasound-guided. The primary outcome is clinical pregnancy rate and the secondary outcome is live birth rate. Statistical analyses were conducted using One-way Anova, Kruscal Whallis H test, chi-square test and Smooth curve fitting. Results When BFD was less than 19 mm, there was no significant change in clinical pregnancy rate as BFD increased (OR = 0.95, 95% CI: 0.89 to 1.02, P = 0.1373); when BFD was more than 19 mm, the clinical pregnancy rate decreased by 16% for every 1 mm increase in BFD (OR = 0.84, 95% CI: 0.72 to 0.98, P = 0.0363). The effect of BFD on live birth rate were similar to that on clinical pregnancy rate, the inflection point was 19mm, when BFD was more than 19 mm, the live birth rate decreases by 58% for every 1 mm increase in BFD (OR = 0.42, 95% CI: 0.21 to 0.86, P = 0.0174) Conclusions The ideal pregnancy outcome can be achieved within 19mm from uterus fundus after single blastocyst transfer, The clinical pregnancy and live birth at a distance of more 19mm from the uterus fundus have a cliff-like downward trend.

Good Practices of Comirnaty® Vaccine Injection Using Uncrimped Materials

Background In 2020, the first mRNA COVID vaccine was approved by the with six doses from single vial. In the context of material shortages, the aim of the study was to compare different protocols to extract doses using uncrimped materials with good trueness and reproducibility. Methods To optimize the extraction of the sixth dose from a single vial with uncrimped materials, alternative protocols of preparation were tested, derived from the drug information. Results The repeatability of injected volume was acceptable for all protocols (CV<5.3%). To prepare six 0.3mL doses using uncrimped materials, protocols with an air bubble were evaluated to offset the high dead volume inherent to uncrimped materials. Regarding the limited doses observed using long intramuscular needle (92.8% of the reference dose), the air bubble protocol with a liquid volume adjustment at 0.27mL was finally validated to respect the administration of full doses. Conclusion Results highlighted the necessity to adapt the drug information protocol for the preparation and administration of Cominarty®, due to the use of high dead volume materials. Despite the good reproducibility and accuracy of the air bubble protocols, some precautions have therefore to be taken to maintain the integrity of the vaccine suspension for efficient administration.