The collapse resulted in the media’s search for immediate answers to the following two questions; why did the bridge collapse and who is to blame? Speculative answers to the first question were proposed by the “Average Joe” and structural engineering experts alike, and involved the usual suspects; the growth from microscopic to catastrophic lengths of undetected cyclic load-induced fatigue crac...

<p class="Abstract">The conventional three-phase alternating current (AC) to direct (DC) converter can be modified using two isolated-gate bipolar transistor (IGBT) as by-pass switches connected tapping points on the secondary side of transformer. This scheme yields a reduction in both harmonic contents and reactive volt-ampere absorption. possibly eliminates need for an on-load tap-chang...

The National Bridge Inventory (NBI) includes more than 600,000 bridges within the United States of Prestressed concrete girder bridges represent one of the most widely used bridge systems. The majority of these girder bridges were constructed using 0.5 and 0.6 inch diameter strands. The main impediments to using larger strand diameters are: 1) bed capacities, 2) lack of structural knowledge reg...

microalloyed s355n steel plates are extensively used in bridge and high-rise building structures. one ofthe factors affecting the mechanical properties is the size and morphology of inclusions. in this research,microalloyed s355n steel plates with different sizes of inclusions were examined. one contained longmanganese sulfide inclusions (li material) and the other had short ones (si material)....

To investigate their adequacy as energy dissipating elements during earthquakes, this paper reports on cyclic inelastic tests executed to determine the maximum strength and ductility of four concrete-filled circular steel piers joined to a foundation detail proposed to develop the full composite strength at the base of these columns. Column diameters considered were 324 and 406 mm, with D/t rat...

The lifetime of a ceramic is dependent on the presence of incidental cracks and their gradual propagation under the conditions of the oral cavity. The objective of this study was to examine the long-term strength of glass-infiltrated alumina- and various zirconia ceramics currently used in CAD/CAM systems to manufacture crown and bridge frameworks. Fracture mechanics were applied to determine c...

Abstract Background Impella is a trans-aortic valvular pump commonly utilized in patients with cardiogenic shock. However, its use transcatheter aortic valves (TAVI) remains rare. We present two cases where surgical 5.5 was placed across both Sapien 3 Ultra and Evolute Pro+ valves. Case Summary Patient 1: 74-year-old male history of ischemic cardiomyopathy ejection fraction 20-25% status post c...

Seeking light and transparent bridge designs, engineers and architects have found an efficient and artistic way to fulfill their requirements: steel tubular bridges. Like any other welded structure, the joints of this kind of bridge suffer from high tensile weld residual stresses. Combined with high stress concentrations, tensile residual stress is a relevant factor in fatigue crack development...

Abstract This study explores an automated method for identifying cracks on a concrete bridge structure using unmanned aerial vehicle (UAV) equipped with high-resolution camera. First, images are captured from the bridge, then novel algorithm used to isolate region of interest. The deep learning detects pre-trained Convolutional Neural Network (CNN) model. proposed was tested Tran Phu and result...

A final report submitted to the Infrastructure Technology Institute DISCLAIMER: The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the information presented herein. This Document is disseminated under the sponsorship of the Synopsis: There have been numerous studies that have aimed at improving the low tensile strength, stiffness, and...