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We established new methods for cloning cDNA ends that start with reverse transcription (RT) and soon proceed with the synthesis of the second cDNA strand, avoiding manipulations of fragile RNA. Our 3'-end cloning method does not involve poly-dT primers and polymerase chain reactions (PCR), is low in efficiency but high in fidelity and can clone those RNAs(More)
In this paper, firstly we find an optimal constant for a convolution problem on the unit circle via the variational method. Then by using the optimal constant, we give a new and improved sufficient condition on the initial data to guarantee the corresponding strong solution blows up in finite time. We also analyze the corresponding ordinary difference(More)
A general methodology for fatigue reliability degradation of railroad wheels is proposed in this paper. Both fatigue crack initiation and crack propagation life are included in the proposed methodology using previously developed multiaxial fatigue models by the same authors. A response surface method in conjunction with design of experiments is used to(More)
This paper proposes two quantitative criteria for removing railroad wheels from service, based on real-time structural health monitoring trends that are developed using data collected from trains while in-service. The data is collected using Wheel Impact Load Detectors (WILDs). These impact load trends are able to distinguish wheels with a high probability(More)
A general methodology for stochastic fatigue life prediction under variable amplitude loading is proposed in this paper. The methodology combines a nonlinear fatigue damage accumulation rule and a stochastic S–N curve representation technique to achieve this objective. The nonlinear damage accumulation rule proposed in this paper improves the deficiencies(More)
A new multiaxial high-cycle fatigue initiation life prediction model for railroad wheels is proposed in this paper. A general fatigue damage analysis methodology for complex mechanical components is developed and applied to the wheel/rail rolling contact fatigue problem. A 3-D elasto-plastic finite element model is used for stress analysis. A submodeling(More)
Two efficient methods for time-dependent fatigue reliability analysis are proposed in this paper based on a random process representation of material fatigue properties and a nonlinear damage accumulation rule. The first method is developed by matching the first two central moments of the accumulated damage to a well-known probability distribution, thus(More)
A unified multiaxial fatigue damage model based on a characteristic plane approach is proposed in this paper, integrating both iso-tropic and anisotropic materials into one framework. Compared with most available critical plane-based models for multiaxial fatigue problem, the physical basis of the characteristic plane does not rely on the observations of(More)
A general framework for probabilistic fatigue damage prognosis using maximum entropy concept is proposed in this paper. The fatigue damage is calculated using a physics-based crack growth model. Due to the stochastic nature of crack growth process, uncertainties arising from the underlying physical model, parameters of the model, and the measurement noise(More)