Study of Shock Attenuation for Impacted Safety Barriers

AbstractRomania is increasing and modernizing its highway network to manage the new transportation system as a result of the development of its economy. It is consequently important that the roads system should be efficiently responsible to the standard traffic requirements. Every safety barrier producer must have an investigation report, known as crash-test. Protective guardrails have as most important aim the redirection of the vehicles on the roadway, ensuring directing pedestrians and other road users. Safety barriers are situated on hazardous road sections in terms of traffic security, to keep vehicles on roadway. Crash-tests are quite expensive and given that they have need of specialized services and qualified personnel, the result is that important decisions are quite often based on the results of a few full-scale impact tests. At present, worldwide, protective guard rails are manufactured in different geometric configurations, depending on different fixing modes in soil, in order to enlarge impact strength capacity for different types of collisions. In this paper, the authors propose and analyze the impact behavior of two new safety guardrail systems in order to raise the impact energy absorption. The tests were performed using as impact or a 1500kg Chevrolet C1500 pick-up truck from the NCAC models library

Optimization Criteria of Plane Lapping Machines

AbstractThis paper reviews experimental research regarding brittle materials processing with superfinishing machine The main criteria for determining the characteristics of superfinishing machines can be grouped into: energy consumption criterion, technologically criterion and dynamic criterion can be determined and the main criteria optimization plan lapping machines. The optimization of the characteristics of brittle materials superfinishing machine is very important because they directly influence the quality of workpieces surfaces. The performances of the superfinishing machine linkages are increasingly higher, due to the following requirements: very high quality workpieces surface, reduced time for feed workpieces to machine tools, better interconnections between machine tools are used in the technological process, high flexibility

Metal Inclusion Influence on Mechanical Behaviour of Plates Made of Araldite

Due to the need for creating new, more efficient, materials for use in structures manufacturing, a high interest issue for researchers and engineers is to analyze the plastic or composite material defects and their influence over the mechanical behavior of the structures. Presented in this paper are the results of experimental analysis and its validation, made by finite element numerical analysis. The first part of the analysis process consisted in obtaining the reference values from plastic plates containing no metallic inclusions, which were analyzes both experimentally and numerically, by subjecting them to a flexural load. A numerical validation of the experimental model was obtained. Next, same kind of numerical and experimental analyses were performed, but this time plastic plates containing metallic inclusions were subjected to the same loads as before. In doing so, the study revealed the local and global influences of inclusions over the mechanical behavior of plastic plates. &nbsp

Native Aortic Valve Endocarditis Complicated by Splenic Infarction and Giant Mitral-Aortic Intervalvular Fibrosa Pseudoaneurysm—A Case Report and Brief Review of the Literature

Background: Pseudoaneurysm of the mitral-aortic intervalvular fibrosa (P-MAIVF) is an unusual complication related to various injuries or conditions which involve the mitro-aortic region; it communicates with the left ventricular outflow tract and is associated with a high-risk of redoubtable complications or sudden death. The cerebral and splenic localizations are frequently seen as manifestations of systemic embolism in infective endocarditis. Currently, there are no specific recommendations related to the diagnosis, management, treatment, or further evolution of patients with P-MAIVF and concomitant splenic infarction. This paper presents the case of a 43-year-old Caucasian woman with a late diagnosis of mixed bicuspid aortic valve disease, affected by an under-detected and undertreated episode of infective endocarditis leading to asymptomatic P-MAIVF. Prime clinical and imagistic diagnosis of splenic infarction indicated further extended investigations were required to clarify the source of embolism. Methods: Integrated multimodality imaging techniques confirmed the unexpected diagnosis of P-MAIVF. Results: The case had a fatal outcome following an uncomplicated yet laborious cardiac surgery. Patient death was attributed to a malignant ventricular arrhythmia. Conclusion: The present case raises awareness by highlighting an unexplained and unexpected splenic infarction association with P-MAIVF as a result of infective endocarditis related to mixed bicuspid aortic valve disease

Native Aortic Valve Endocarditis Complicated by Splenic Infarction and Giant Mitral-Aortic Intervalvular Fibrosa Pseudoaneurysm—A Case Report and Brief Review of the Literature

Background: Pseudoaneurysm of the mitral-aortic intervalvular fibrosa (P-MAIVF) is an unusual complication related to various injuries or conditions which involve the mitro-aortic region; it communicates with the left ventricular outflow tract and is associated with a high-risk of redoubtable complications or sudden death. The cerebral and splenic localizations are frequently seen as manifestations of systemic embolism in infective endocarditis. Currently, there are no specific recommendations related to the diagnosis, management, treatment, or further evolution of patients with P-MAIVF and concomitant splenic infarction. This paper presents the case of a 43-year-old Caucasian woman with a late diagnosis of mixed bicuspid aortic valve disease, affected by an under-detected and undertreated episode of infective endocarditis leading to asymptomatic P-MAIVF. Prime clinical and imagistic diagnosis of splenic infarction indicated further extended investigations were required to clarify the source of embolism. Methods: Integrated multimodality imaging techniques confirmed the unexpected diagnosis of P-MAIVF. Results: The case had a fatal outcome following an uncomplicated yet laborious cardiac surgery. Patient death was attributed to a malignant ventricular arrhythmia. Conclusion: The present case raises awareness by highlighting an unexplained and unexpected splenic infarction association with P-MAIVF as a result of infective endocarditis related to mixed bicuspid aortic valve disease