Search results for "Ridge"
showing 10 items of 531 documents
Nuclear Energy Density Optimization: UNEDF2
2014
The parameters of the UNEDF2 nuclear energy density functional (EDF) model were obtained in an optimization to experimental data consisting of nuclear binding energies, proton radii, odd-even mass staggering data, fission-isomer excitation energies, and single particle energies. In addition to parameter optimization, sensitivity analysis was done to obtain parameter uncertainties and correlations. The resulting UNEDF2 is an all-around EDF. However, the sensitivity analysis also demonstrated that the limits of current Skyrme-like EDFs have been reached and that novel approaches are called for.
BEF Analogy for Concrete Box Girder Analysis of Bridges
2010
<p>Box girder, due to its high torsional stiffness, is very appropriate for railway and highway long- medium span bridges. This type of cross section, subjected to transversely non-uniform loads, present warping and distortion phenomena. Accurate but time-consuming numerical procedures are available for determination of further strains and stresses caused by cross-section deformation. In this paper warping and distortion of box girders is evaluated through BEF analogy, by writing a 4th order differential equation. The problem is solved for practical cases of box girders by considering internal diaphragms stiffness. Graphs are supplied to designers and main design parameters affecting …
Crumpling of a stiff tethered membrane.
2003
first-principles numerical simulation model for crumpling of a stiff tethered membrane is introduced. In our model membranes, wrinkles, ridge formation, ridge collapse, as well as the initiation of stiffness divergence, are observed. The ratio of the amplitude and wave length of the wrinkles, and the scaling exponent of the stiffness divergence, are consistent with both theory and experiment. We observe that close to the stiffness divergence there appears a crossover beyond which the elastic behavior of a tethered membrane becomes similar to that of dry granular media. This suggests that ridge formation in membranes and force-chain network formation in granular packings are different manife…
Risk of failure for the salso river railroad steel bridge
2020
Abstract The degradation state of railroad steel bridges is one of the most important and difficult aspects to be interpreted. The use of steel bridges started from 1900, and they are still in service today as railroad bridges. The case study examined was that of a bridge railroad steel bridge having a total length of 112 m and constituted by three isostatic, reticular beams having a Pratt type composition. The substructures (two shoulders and two intermediate piles) are in masonry with a reinforced concrete beam in the upper portion. The structure (steel bridge and piers) is in a degraded state. To determine the degradation level, non-destructive and partially destructive tests were carrie…
Innovative Computational Approach to Harmonic Mitigation for Seven-level Cascaded H-Bridge Inverters
2020
Low frequency modulation strategies are a good solution to increase the energy conversion efficiency in high power applications. The paper is devoted to presents an innovative way to low order harmonics mitigation for seven-level Cascaded H-Bridge Inverters. In particular, this approach is based on the mitigation of selected harmonics without solve non-linear equations for an extended range of the fundamental amplitude. In fact, in real-Time operation to evaluate the control angles the polynomial equations have been identified. Through circuit simulation analysis in MatLab/PLECS environment, the effectiveness of the harmonic mitigation method has been tested and compared with theoretical re…
Novel Computational Method for Harmonic Mitigation for Three-phase Five-level Cascaded H-Bridge Inverter
2018
The efficiency of the system is a very important parameter for high power electrical drives applications,. Moreover, in the system the efficiency of the power converter play a fundamental role and for this reason, the soft switching modulation techniques represent the best choice. This paper presents a novel computational method for harmonic mitigation on the output voltage of a five-level, three-phase Cascaded H-Bridge Inverter without solving non-linear equations. Through this simple approach the Working Areas have been identified in which the harmonics reference have minimum amplitude possible. Moreover, polynomial equations to evaluate the control angels have been found. In this way, th…
Selective harmonic mitigation with asymmetrical staircase voltage waveform for a three-phase five-level Cascaded H-Bridge Inverter
2020
Selective harmonics elimination or mitigation strategies are used in all applications where it is necessary to rise the efficiency and reliability of the overall system. This paper presents a simple approach to reduce the low order harmonics amplitude of an asymmetrical staircase voltage waveform for a five-level, three-phase Cascaded H-Bridge Inverter without solving non-linear equations. Through this simple approach, polynomial equations to evaluate the control angels in real-time operations have been found. The effectiveness of the harmonic mitigation method has been tested through the simulation analysis in MatLab/PLECS environment.
COMPORTAMENTO DI IMPALCATI DA PONTE A CASSONE IN ACCIAIO-CALCESTRUZZO CON ANIMA ONDULATA
2013
La memoria riguarda il comportamento di un impalcato di ponte stradale a cassone avente le anime sagomate secondo una sinusoide, con soletta in c.a. collaborante. L'impalcato presenta schema statico longitudinale di trave continua su 4 appoggi. The paper concerns the behaviour of a box-girder bridge deck road having a steel box and a concrete slab. The steel webs are shaped according to a sine wave. The deck has a width of 13.70 m and a length of 182 m, with the longitudinal static scheme as a continuous beam on four supports. The study highlights the reliability of this constructive solution.
Boys Will Be Boys? Subverting Traditional Power Structures in Asian-American Prose
2013
Leaving one’s home country behind and starting a new life on a different continent may also involve being confronted with behaviors and values completely different from the ones that were deemed the only ones back home. This experience is described by the protagonist of the Asian-American author Amy Tan’s story “The Red Candle”, recalling her arrival in California from a small village in China. In her attempt to bridge the gap between the conflicting worlds of “Old East and New West”, the protagonist uses concepts and metaphors that might be transferred and prove valuable in more than one cultural context. In the hierarchy of the culture which is described, a position of power is most of al…
Performance of a historical cantilever reinforced concrete bridge with half-joint degradation
2022
The lack of maintenance of roadway concrete bridges built from the Second World War until the 70 s of the 20th century has led in recent years to an ever-increasing request for safety assessments. When bridge performance in terms of Serviceability Limit State (SLS) and Ultimate Limit State (ULS) has to be evaluated, in-situ visual inspections and load tests for safety and maintenance assessment have to be coupled with structural analysis. In order to identify a sound bridge structural model and to assess the actual conservation state, more refined models than those usually considered for section and reinforcement design should be used to reproduce the results of load tests and perform globa…