Study of thermal insulation for airborne liquid hydrogen fuel tanks

A concept for a fail-safe thermal protection system was developed. From screening tests, approximately 30 foams, adhesives, and reinforcing fibers using 0.3-meter square liquid nitrogen cold plate, CPR 452 and Stafoam AA1602, both reinforced with 10 percent by weight of 1/16 inch milled OCF Style 701 Fiberglas, were selected for further tests. Cyclic tests with these materials in 2-inch thicknesses bonded on a 0.6-meter square cold plate with Crest 7410 adhesive systems, were successful. Zero permeability gas barriers were identified and found to be compatible with the insulating concept

Smile outcomes when using masseteric nerve-based nerve transfers versus direct muscle neurotization in facial palsy patients

Background: When dealing with a weak smile, nerve transfer is a viable strategy. We evaluated outcomes of masseteric nerve to facial nerve transfers and compared them with direct muscle neurotization (DMN). Methods: In a retrospective cohort study of 20 patients (n = 20), we compared nerve transfer versus DMN over a 6-year period (2016–2021). Outcomes were measured using the validated Sunnybrook score, Ackerman Smile Index, and Terzis scores. Statistical analysis was performed using the Wilcoxon sign rank and Mann-Whitney U tests. Results: Comparing pre- versus postoperative scores after nerve transfers, there was a significant improvement in median overall Sunnybrook score (24 versus 47, P = 0.043), lip elevation (1 versus 2, P = 0.046), open mouth smile (1 versus 3, P = 0.003), and Terzis scores (1 versus 3, P = 0.005), with no difference in resting symmetry (−15 versus −5; P = 0.496). Compared with DMN, there was no difference in median Terzis score improvement from preoperative to postoperative state (2 versus 1, P = 0.838), median smile improvement (2 versus 2, P = 0.838), resting symmetry (10 versus 5, P = 0.144) or overall Sunnybrook score (23 versus 21, P = 1.000). Lip elevation improvement was in favor of nerve transfers (1 versus 0, P = 0.047). Conclusions: This is the first study evaluating nerve transfer neurotization of smile-mimetic muscles and comparing the outcomes with DMN, with masseteric nerve as donor. Nerve transfer leads to improved facial mimetic function, smile excursion and open mouth smiles, as does DMN, with improvement in lip elevation in favor of nerve transfer. Nerve transfer was preferred for more severe smile weakness