Results 1 - 10 of 1537
Results 1 - 10 of 1537. Search took: 0.025 seconds
|Sort by: date | relevance|
[en] The study of the ultrasonic technique of elapsed time in the dimensionment of notch inclined of 15 and 30 degree and of depth of 5 and 10 mm using the superficial Rayleigh wave and the mode conversion, with a headstock transmitter and other receiver. The dimensionment of notch and of the binding of the piece were made with headstock in different positions. Between the various results obtained can be mentioned the increase of the dimensionment, by two techniques, with the increase of the angle and/or of the depth. (V.R.B.)
[en] This paper proposed a methodology based on ultrasonic diffraction technique to inspect the depth of a crack initiated from a notch of CT specimen by fatigue test, and its usefulness was verified by experiments. Especially, in order to identify accurately the diffractive waves from the crack tip in the situation where there are extra diffractive elements such as a notch, we have tried imaging by transducer scan and analyzed the propagation path of diffracted wave. Two specimens with and without a crack were experimented. Higher frequency and larger refractive angle of transducer showed a tendency to decrease the error in the measurements, and the measured crack depth showed an error less than 0.38 mm in case of 4 MHz 60 .deg. - 60 .deg. . The proposed methodology is applicable to weak diffractive sources, and so that it would be useful to inspect micro cracks and for their depth sizing
[en] For pipe beams with a stable crack under bending only, Petroski proposed that the cracked section yields at a reduced bending moment M p=γM 0 with γ<1 being a reduction factor. A Reduction Factor Approach is defined in this paper to approximately construct the yield loci of notched/cracked members under various complex generalized loading states. By introducing a reduction factor γ into the yield functions of the perfect member, the interactive yield loci for a V-shape notched/cracked member under interactions between bending and tension, between bending and shear, or amongst bending, tension and shear, are straightforwardly constructed. When tension n is involved, a term (i.e. 2cn) arising from the effect of ligament eccentricity should be added to the bending moment m. The approximate yield loci can be expressed in analytical forms, facilitating applications in engineering analyses when complex generalized loading states are involved. The yield surfaces tabulated in Lee and Parks  are consistently fitted by a concise analytical expression whose form is suggested by the present approach
[en] High-throughput molecular profiling approaches have emerged as precious research tools in the field of head and neck translational oncology. Such approaches have identified and/or confirmed the role of several genes or pathways in the acquisition/maintenance of an invasive phenotype and the execution of cellular programs related to cell invasion. Recently published new-generation sequencing studies in head and neck squamous cell carcinoma (HNSCC) have unveiled prominent roles in carcinogenesis and cell invasion of mutations involving NOTCH1 and PI3K-patwhay components. Gene-expression profiling studies combined with systems biology approaches have allowed identifying and gaining further mechanistic understanding into pathways commonly enriched in invasive HNSCC. These pathways include antigen-presenting and leucocyte adhesion molecules, as well as genes involved in cell-extracellular matrix interactions. Here we review the major insights into invasiveness in head and neck cancer provided by high-throughput molecular profiling approaches
[en] In this paper, 3-dimensional fracture phenomena in the local area near a through notch tip located between the surface and the canter were investigated by using embedded dyeing grids with the pitch of 50.8μm. It was confirmed that displacement V and square root of distance from notch tip y1/2 are not proportional in the local area of √|y| <0.3mm1/2 and the maximum shea strain εxymax near a notch tip occurred at the curvature beginning point of the notch curve. It was also noted that the maximum strain εmax in the thickness direction occurred at the interior, where the ratio of the distance measured from surface to the half of thickness of specimen is 0.3
[en] A shear horizontal (SH) guided wave mode was applied to detect a crack in a aluminum plate. A bar-type magnetostrictive sensor was used to generate and receive shear horizontal guided ultrasound. Artificial notches with various depths and widths were fabricated in an aluminum plate of 5 mm thickness. Detectability was examined at various angle from the distance of 0.8 m on the specimen with the frequency of 64 kHz and 128 kHz.
[en] The methodology of probabilistic fatigue life prediction for notched components based on smooth specimens is presented. Weakestlink theory incorporating Walker strain model has been utilized in this approach. The effects of stress ratio and stress gradient have been considered. Weibull distribution and median rank estimator are used to describe fatigue statistics. Fatigue tests under different stress ratios were conducted on smooth and notched specimens of titanium alloy TC-1-1. The proposed procedures were checked against the test data of TC-1-1 notched specimens. Prediction results of 50 % survival rate are all within a factor of two scatter band of the test results
[en] Impaction of tooth is a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise located so that it cannot erupt normally. The supernumerary tooth is also called as hyperdontia and defined as the condition of having additional tooth to the regular number of teeth. The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary incisors. The supernumerary tooth is commonly impacted but they are frequently impacted on maxilla. Ectopic impaction of supernumerary tooth on mandibular condyle, coronoid process, ascending ramus, and pterygomandibular space is very rare condition. In this case, we report a case of impacted supernumerary tooth on mandibular sigmoid notch without definite pathologic change.
[en] We have carried out a systematic study on domain wall (DW) pinning at an anti-notch in a Ni80Fe20 nanowire. Micromagnetic studies reveal that the potential polarity experienced by the DW at the anti-notch is a function of both DW chirality and anti-notch geometry. A transition in the potential disruption experienced by the DW is observed when the anti-notch height-to-width ratio (HAN/WAN) is 2. This transition is due to the relative orientation of the spins in the anti-notch with respect to the transverse component of the DW. When the anti-notch acts as a potential barrier, the DW undergoes damped oscillations prior to coming to an equilibrium position. The equilibrium position is a strong function of the anti-notch dimensions when the HAN/WAN ratio <2 and is constant for HAN/WAN ≥ 2. The effect of the relative orientation between the spins in the anti-notch and the transverse component of the DW on the shape of the potential is discussed.