Testing and modeling of an in situ shear exfoliated 2D nanocomposite coating casing material for the suppression of Li-ion battery fires in electric vehicles

A two-dimensional nanocomposite coating material, a mixture of dragon skin®(DS) (flame-resistant silicone elastomer and hexagonal boron nitride(hBN) (DS/hBN), was applied on the traditional polycarbonate battery casing material to study its effect on flame retardancy. A micro-batch mixer was used to simultaneously exfoliate hBN nanosheets from bulk layered hBN raw materials and disperse these nanolayers into both dragon skin polymer precursor and curing agent. Standard ‘UL94 Flammability Test’ protocol was followed to measure the flame retardancy of the prepared coating. The test showed enhanced flame retardancy in horizontal and vertical tests for DS/hBN sample as compared to the DS sample, which followed the trend found in numerical simulation. Additionally, the mechanical strength of DS/hBN-coated battery casing material remained intact even after prolonged flame exposure. This opens the door for manufacturing of low-cost hBN coating for robust electric vehicle battery casings

Sub-classification of laparoscopic left hepatectomy based on hierarchic interaction of tumor location and size with perioperative outcomes

Background: The aim of this multicentric study was to investigate the impact of tumor location and size on the difficulty of Laparoscopic- Left Hepatectomy (L- LH).Methods: Patients who underwent L- LH performed across 46 centers from 2004 to 2020 were analyzed. Of 1236 L- LH, 770 patients met the study criteria. Baseline clinical and surgical characteristics with a potential impact on LLR were included in a multi-label conditional interference tree. Tumor size cut -off was algorithmically determined. Results: Patients were stratified into 3 groups based on tumor location and dimension: 457 in antero-lateral location (Group 1), 144 in postero-superior segment (4a) with tumor size = 40 mm (Group 2), and 169 in postero-superior segment (4a) with tumor size >40 mm (Group 3). Patients in the Group 3 had higher conversion rate (7.0% vs. 7.6% vs. 13.0%, p- value .048), longer operating time (median, 240 min vs. 285 min vs. 286 min, p-value 40 mm in diameter and located in PS Segment 4a are associated with the highest degree of technical difficulty. However, post-operative outcomes were not different from L- LH of smaller tumors located in PS segments, or tumors located in the antero-lateral segments