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Impact Attenuator Optimum Design for a FSAE Racing Car by Numerical and Experimental Crash Analysis
Coppola Ludovica,De Marco Bruno,Niola Vincenzo,Sakhnevych Aleksandr,Timpone Francesco 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.6
One of the most important requirements of the Formula SAE (Society of Automotive Engineers) race cardesign competition is that the car structure must guarantee a high protection level in case of frontal impacts, by preventing intrusions into the driver foot zone or dangerous deceleration levels. These functions are mainly performed by the impact attenuators, which have to guarantee a high specific energy absorption capacity (SEA) and in order to preserve vehicle performances, have to be as light weighted as possible. The aim of this study is the design of an impact attenuator, to be mounted on a Formula SAE car, which main purpose is to obtain the optimal crash energy management, maximizing the absorbed energy and optimizing the geometry. The outcome of the study highlights that the absorber structure made up of honeycomb sandwich panels (primary energy absorbers), realized by means of different aluminium alloys employing an innovative design considering particular geometrical cavities within the structure, could lead to reduce the overall weight and to achieve a more progressive deformation during the impact.
Martina Ferrillo,Dario Calafiore,Lorenzo Lippi,Francesco Agostini,Mario Migliario,Marco Invernizzi,Amerigo Giudice,Alessandro de Sire 대한치과교정학회 2024 대한치과교정학회지 Vol.54 No.1
Objective: This systematic review aimed to evaluate the correlation between vitamin D levels and the rate of tooth movement, external apical root resorption, bone biomarker expression, and bone remodeling. Methods: Three databases (PubMed, Scopus, and Web of Science) were systematically searched from inception until 14th March 2023 to identify studies investigating the correlation between orthodontic tooth movement and vitamin D in animals and humans. The quality assessment was made in accordance with the Joanna Briggs Institute Critical Appraisal Checklist. Results: Overall, 519 records were identified, and 19 were selected for the qualitative synthesis. Eleven studies investigated the effect of local administration (injections in the periodontal ligament, to the gingiva distal to the teeth, or submucosae palatal area) and systemic administration (oral supplementation) of vitamin D on tooth movement, external apical root movement, pro-inflammatory cytokines, and bone remodeling factors. The remaining eight studies investigated the correlation between serum vitamin D levels and salivary vitamin D levels on bone turnover markers and tooth movement. Conclusions: The findings of this systematic review support that vitamin D3 local injections might increase the rate of tooth movement via the receptor activator of the nuclear factor-kB/osteoprotegerin axis. However, the non-uniform study designs and the different protocols and outcome methods make it challenging to draw reliable conclusions.
Alessia Chini,Michele Manigrasso,Grazia Cantore,Rosa Maione,Marco Milone,Francesco Maione,Giovanni Domenico De Palma 대한소화기내시경학회 2022 Clinical Endoscopy Vol.55 No.2
Colorectal cancer is an important cause of morbidity and mortality worldwide. Optical colonoscopy (OC) is widely accepted as thereference standard for the screening of colorectal polyps and cancers, and computed tomography colonography (CTC) is a validalternative to OC. The purpose of this review was to assess the diagnostic accuracy of OC and CTC for colorectal lesions. A literaturesearch was performed in PubMed, Embase, and Cochrane Library, and 18 articles were included. CTC has emerged in recent years asa potential screening examination with high accuracy for the detection of colorectal lesions. However, the clinical application of CTCas a screening technique is limited because it is highly dependent on the size of the lesions and has poor performance in detectingindividual lesions <5 mm or flat lesions, which, although rarely, can have a malignant potential.