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1.
Sci Rep ; 14(1): 8531, 2024 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609470

RESUMO

This study presents a thorough numerical evaluation of the crashworthiness properties of a new bio-inspired DNA tubes (BIDNATs) with circular, elliptical, and rectangular cross-sections. Deformation and crashworthiness behaviors are evaluated using axial quasi-static crushing simulations by ABAQUS/Explicit (Abaqus 6.14, https://www.3ds.com/products-services/simulia/products/abaqus/ ). The study compares the performance of conventional tubes with rectangular and elliptical cross-sections to DNA-inspired tubes. Increasing the rotation angle leads to more helices and a pronounced helix angle, resulting in lower initial peak force (IPF). However, lower cross-section aspect ratios generally have higher IPF and specific energy absorption (SEA) values. BIDNATs with rectangular cross-sections and a 540° rotation angle have the lowest SEA and IPF values across all aspect ratios. Notably, for the 110/100 aspect ratio, the SEA of E110/100 is 71% higher than the conventional tube. Overall, BIDNATs with elliptical cross-sections and a 360° rotation angle exhibit higher SEA values and lower IPF values, particularly for a width (W) of 100 mm. Conventional circular and elliptical tubes generally have SEA values exceeding 6 J/g, with only E110/100 surpassing this among DNA-inspired tubes. The NE110/100 tube has the highest SEA, surpassing E110/100 by 54%, while its IPF is 10% greater than DNA-inspired E110/100. It's worth noting that conventional circular and elliptical tubes have higher IPF values compared to their DNA-inspired counterparts. These findings offer valuable insights for engineers and researchers in the design of crash tubes to improve overall vehicle safety for both occupants and pedestrians.


Assuntos
DNA , Pedestres , Humanos , Engenharia , Pesquisadores , Rotação
2.
Indian J Otolaryngol Head Neck Surg ; 71(2): 206-211, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31275832

RESUMO

Anthropometry is a scientific study of linear dimensions and angles of living subjects. Knowing the details and anthropometric properties of nasofacial for each specific ethnic group is important for cosmetic operation as well as identifying individuals. In this study, facial and nasal anthropometric factors were studied in students of Shiraz University of Medical Sciences. In a cross-sectional study, 200 students of Shiraz University of Medical Sciences (100 male and 100 female and age range of 18-30 years) were selected. Nasal width (NW), nasal length (NL), nasal height (NH), face height (FH) and face width (FW) were measured in and the nasal (NI) and facial index (FI) were calculated for each case. Then, the data were analyzed using SPSS-22. The mean age was 21.84 ± 3.18 years. There were significant differences in the facial and nasal measurements including FH (P = 0.0001), FW (P = 0.0001), FI (P = 0.0001), NL (P = 0.002), NH (P = 0.001), NW (P = 0.0001) and NI (P = 0.0001) of sex groups. The most common types of face were mesoprosopic (36%) and hyperleptoprosopic (38%) types and and platyrrhine (63%) were mostly frequent. Based on the findings, all students of Shiraz University of Medical Sciences had mesoprosopic (36%) and hyperleptoprosopic (38%) types of face and platyrrhine type of nose. As well, a sexual dimorphism was recorded according to the nasofacial measurements in Iranian population that should be considered in the cosmetic operations. Sexual dimorphism and differences between different populations were recorded.

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