1,428 research outputs found
High-directivity acoustic antenna
Acoustic antenna with unique electronic steering control is used to identify and define aerodynamic noise sources in free field, particularly in wind tunnel which is quite reverberant. Provision is made for high directivity as well as improved discrimination against unwanted background noise such as reverberation or echoes
Analytical study of acousto/optical holography-interfacing methods for acoustical and optical holography NDT research
The international status of the art of acousto optical imaging techniques adaptable to nondestructive testing and, interfacing methods for acoustical and optical holography in nondestructive testing research are studied. Evaluation of 20 different techniques encompassed investigation of varieties of detectors and detection schemes, all of which are described and summarized. Related investigation is reported in an Appendix. Important remarks on image quality, factors to be considered in designing a particular system, and conclusions and recommendations are presented. Three bibliographies are included
Stratigraphic succession and depositional framework of the Sandakan Formation, Sabah
The Sandakan Formation of the Segama Group is exposed across the Sandakan Peninsular in eastern Sabah. This Upper Miocene part of the Segama Group unconformably overlies the Garinono Formation and is conformably overlain by the Bongaya Formation. This formation was investigated with detailed logging of outcrops and microfossils analysis in order to map the depositional facies and sedimentary environment. This study showed the presence of seven lithofacies: Thick amalgamated sandstone; thin, lenticular interbedded HCS sandstones and mudstone; laminated mudstone with Rhizophora; trough cross-bedded sandstone; laminated mudstone; strip mudstone with thin sandstone and siltstone; and interbedded HCS sandstone and mudstone. Based on the presence of Rhizophora, Brownlowia, Florchuetia sp., Polypodium, Stenochleana palustris, Ascidian spicule low angle cross bedding, very fine grained sandstone, thin alternations of very fine sandstone, silt and clay layers showing cyclicity (muddy rhythemites), rocks in the Sandakan Formation are interpreted as mangal estuary and open marine facies. Three facies associations could be deduced from the seven lithofacies: Gradual coarsening upwards shoreface; abrupt change facies and prograding estuary facies association
Effects of the Lattice Discreteness on a Soliton in the Su-Schrieffer-Heeger Model
In this paper we analytically study the effects of the lattice discreteness
on the electron band in the SSH model. We propose a modified version of the TLM
model which is derived from the SSH model using a continuum approximation. When
a soliton is induced in the electron-lattice system, the electron scattering
states both at the bottom of the valence band and the top of the conduction
band are attracted to the soliton. This attractive force induces weakly
localized electronic states at the band edges. Using the modified version of
the TLM model, we have succeeded in obtaining analytical solutions of the
weakly localized states and the extended states near the bottom of the valence
band and the top of the conduction band. This band structure does not modify
the order parameters. Our result coincides well with numerical simulation
works.Comment: to be appear in J.Phys.Soc.Jpn. Figures should be requested to the
author. They will be sent by the conventional airmai
Subtraction electrocardiography: Detection of ischemia-induced ST displacement without the need to identify the J point
AbstractBackgroundWhen triaging a patient with acute chest pain at first medical contact, an electrocardiogram (ECG) is routinely made and inspected for signs of myocardial ischemia. The guidelines recommend comparison of the acute and an earlier-made ECG, when available. No concrete recommendations for this comparison exist, neither is known how to handle J-point identification difficulties. Here we present a J-point independent method for such a comparison.MethodsAfter conversion to vectorcardiograms, baseline and acute ischemic ECGs after 3minutes of balloon occlusion during elective PCI were compared in 81 patients of the STAFF III ECG database. Baseline vectorcardiograms were subtracted from ischemic vectorcardiograms using either the QRS onsets or the J points as synchronization instants, yielding vector magnitude difference signals, ΔH. Output variables for the J-point synchronized differences were ΔH at the actual J point and at 20, 40, 60 and 80ms thereafter. Output variables for the onset-QRS synchronized differences were the ΔH at 80, 100, 120, 140 and 160ms after onset QRS. Finally, linear regressions of all combinations of ΔHJ+… versus ΔHQRS+… were made, and the best combination was identified.ResultsThe highest correlation, 0.93 (p<0.01), was found between ΔH 40ms after the J point and 160ms after the onset of the QRS complex. With a ΔH ischemia threshold of 0.05mV, 66/81 (J-point synchronized differences) and 68/81 (onset-QRS synchronized differences) subjects were above the ischemia threshold, corresponding to sensitivities of 81% and 84%, respectively.ConclusionOur current study opens an alternative way to detect cardiac ischemia without the need for human expertise for determination of the J point by measuring the difference vector magnitude at 160ms after the onset of the QRS complex
Ginseng and Anticancer Drug Combination to Improve Cancer Chemotherapy: A Critical Review
Ginseng, a well-known herb, is often used in combination with anticancer drugs to enhance chemotherapy. Its wide usage as well as many documentations are often cited to support its clinical benefit of such combination therapy. However the literature based on objective evidence to make such recommendation is still lacking. The present review critically evaluated relevant studies reported in English and Chinese literature on such combination. Based on our review, we found good evidence from in vitro and in vivo animal studies showing enhanced antitumor effect when ginseng is used in combination with some anticancer drugs. However, there is insufficient clinical evidence of such benefit as very few clinical studies are available. Future research should focus on clinically relevant studies of such combination to validate the utility of ginseng in cancer
Fluorophore-Doped Core-Multishell Spherical Plasmonic Nanocavities: Resonant Energy Transfer towards a Loss Compensation
Cataloged from PDF version of article.Plasmonics exhibits the potential to break the diffraction limit and bridge the gap between electronics and
photonics by routing and manipulating light at the nanoscale. However, the inherent and strong energy
dissipation present in metals, especially in the near-infrared and visible wavelength ranges, significantly
hampersthe applications in nanophotonics. Therefore, it is amajor challengetomitigatethe losses. One way
to compensate the losses is to incorporate gain media into plasmonics. Here, we experimentally show that
the incorporation of gain material into a local surface plasmonic system (Au/silica/silica dye core multishell
nanoparticles) leads to a resonant energy transfer from the gain media to the plasmon. The optimized
conditions for the largest loss compensation are reported. Both the coupling distance and the spectral
overlap arethe key factorsto determinetheresulting energy transfer. Theinterplay of these factors leadsto
a non-monotonous photoluminescence dependence as a function of the silica spacer shell thickness.
Nonradiativetransferrate is increased by morethan 3 orders of magnitude attheresonant condition, which
is key evidence of the strongest coupling occurring between the plasmon and the gain material
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