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In this study we constructed a special three-in-one resonance tube for a harmonic series sound waves experiment. It is designed for three different experiments:both-open-end, one-closed-end and both-closed-end tubes. The resonance...
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In this study we constructed a special three-in-one resonance tube for a harmonic series sound waves experiment. It is designed for three different experiments:both-open-end, one-closed-end and both-closed-end tubes. The resonance tube consists of a PVC conduit with a rectangular hole, rubber tube, plastic stopper with an embedded microphone and a plastic stopper. The resonance tube is utilized with visual analyser freeware to detect, display and measure the resonance frequencies for each harmonic series. The speeds of sound in air, v, are determined from the gradient of the 2(L + e) versus n_n~(f-1), 4(L + e) versus n f_n~(-1) and 2L versus n f_n~(-1) graphs for both-open-end, one-closedend and both-closed-end tubes, respectively. The compatibility of a resonance tube for a harmonic series experiment is determined by comparing the experimental and standard values of v. The use of a resonance tube produces accurate results for v within a 1.91% error compared to its standard value. It can also be used to determine the values of end correction, e, in both-openend and one-closed-end tubes. The special resonance tube can also be used for the values of n for a harmonic series experiment in the three types of resonance tubes:both-open-end, one-closed-end and both-closed-end tubes.
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In a dramatic physics demonstration, a professional flutist produces four resonances with a 12 ounce Boylan soda bottle solely through her breath control. The 22 cm bottle acts like a Helmholtz resonator for the lowest pitch. The ...
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In a dramatic physics demonstration, a professional flutist produces four resonances with a 12 ounce Boylan soda bottle solely through her breath control. The 22 cm bottle acts like a Helmholtz resonator for the lowest pitch. The three higher pitches fall near the 3rd, 5th, and 7th harmonics for a 22 cm closed pipe. A video of this remarkable feat is provided (Ruiz 2016 YouTube: Four Resonances with a 12-ounce Soda Bottle (https://youtu.be/ ibtVrp2NF_k)). The video also reveals that a flutist can bend resonance pitches by as much as 10% through control of air speed.
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Functional magnetic resonance imaging (fMRI) is a methodology for detecting dynamic patterns of activity in the working human brain. Although the initial discoveries that led to fMRI are only about 20 years old, this new field has...
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Functional magnetic resonance imaging (fMRI) is a methodology for detecting dynamic patterns of activity in the working human brain. Although the initial discoveries that led to fMRI are only about 20 years old, this new field has revolutionized the study of brain function. The ability to detect changes in brain activity has a biophysical basis in the magnetic properties of deoxyhemoglobin, and a physiological basis in the way blood flow increases more than oxygen metabolism when local neural activity increases. These effects translate to a subtle increase in the local magnetic resonance signal, the blood oxygenation level dependent (BOLD) effect, when neural activity increases. With current techniques, this pattern of activation can be measured with resolution approaching 1 mm3 spatially and 1 s temporally. This review focuses on the physical basis of the BOLD effect, the imaging methods used to measure it, the possible origins of the physiological effects that produce a mismatch of blood flow and oxygen metabolism during neural activation, and the mathematical models that have been developed to understand the measured signals. An overarching theme is the growing field of quantitative fMRI, in which other MRI methods are combined with BOLD methods and analyzed within a theoretical modeling framework to derive quantitative estimates of oxygen metabolism and other physiological variables. That goal is the current challenge for fMRI: to move fMRI from a mapping tool to a quantitative probe of brain physiology.
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Micro- and nano-electromechanical systems (M/NEMS) have demonstrated outstanding sensing capabilities down to the yoctogram (10(-24) g) scale in vacuum environment and cryogenic temperatures. In order to bring such extraordinary r...
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Micro- and nano-electromechanical systems (M/NEMS) have demonstrated outstanding sensing capabilities down to the yoctogram (10(-24) g) scale in vacuum environment and cryogenic temperatures. In order to bring such extraordinary resolution levels into the study of biological processes, suspended microchannel resonators (SMRs) have been developed. SMRs are hollow devices allowing for fluidic confinement inside the body of the resonator, which can thus be kept in dry environment or encapsulated in vacuum. Analyte binding and flowthrough experiments can be performed, these latter enabling single-cell analysis. In this paper, we survey the progress of over the past 20 years in the field of SMRs. We review the main fabrication, transduction and packaging strategies. We also provide an insight into the working principle of the sensors and their applications to microfluidics and biology.
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Fano resonance spectroscopy (FRS) is used to investigate the photonic resonance properties of the defect states in two-dimensional finite-sized photonic crystals (PCs). This study examines the scattering cross-section spectra by c...
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Fano resonance spectroscopy (FRS) is used to investigate the photonic resonance properties of the defect states in two-dimensional finite-sized photonic crystals (PCs). This study examines the scattering cross-section spectra by changing the direction of the incident light continuously. The present FRS is applied to the intrinsic localized defect produced by displacing a single rod atom from its regular site, which creates one defect mode within the first gap and two defect modes within the second gap simultaneously. The present examination has made clear the correlation between the asymmetry of the scattering cross-section spectra-characterized by the so-called Fano q value-and the optical energy flows in the PC, in particular, that the optical incoming flux is maximized for q~(-1) = 0. This fact demonstrates the presence of the selective capturing of photons at the defect state in the incoming process of light; moreover, it can be recognized merely by knowledge of the q values. The Fano resonances have thus been successfully used to elucidate the resonance nature of the localized defect states in photonic crystals.
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Stub and ring resonators with resonance frequency micromechanical tuning are presented.Benefits and main differences of micromechanical resonance frequency tuning method from other methods are shown.Normalized dependences of effec...
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Stub and ring resonators with resonance frequency micromechanical tuning are presented.Benefits and main differences of micromechanical resonance frequency tuning method from other methods are shown.Normalized dependences of effective permittivity on normalized air gap values for various microstrip line electrode width to substrate height ratios are obtained.Effective permittivity analytical formulas for the case of infinitely wide electrodes are derived.Calculated and experimental dependences of resonance frequency on air gap value and stub experimental unloaded quality factor dependences are given.Air gap influence on resonance frequency value depending on substrate permittivity is shown in terms of the resonance frequency sensitivity.Error estimation for measured experimental data is presented.Adding tunable heterogeneity between the microstrip resonator signal electrode and the substrate provides not only the resonance frequency tuning but preserves unloaded quality factor.The preservation of the unloaded quality factor during the resonance frequency tuning achieved due to the metal and dielectric loss reduction.Air gap doesn’t have dissipative losses and has permittivity of one,which makes it the best solution for unloaded quality factor preservation.Another important conclusion is that insertion of the air heterogeneity reduces values of dielectric and metal losses arising when substrates with high permittivity are used.For dielectric loss reduction,it is important to maintain low ratio of microstrip line width to substrate height.In contrast to dielectric losses for metal loss reduction the ratio of microstrip line width to substrate height should be high.However,that ratio is limited by impedance permissible range.
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Bound and resonance states of a two-electron quantum dot are studied using a variational expansion with real basis-set functions. The two-electron entanglement (von Neumann entropy) is calculated as a function of the quantum-dot s...
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Bound and resonance states of a two-electron quantum dot are studied using a variational expansion with real basis-set functions. The two-electron entanglement (von Neumann entropy) is calculated as a function of the quantum-dot size at both sides of the critical size, where the ground (bound) state becomes a resonance (unbound) state. The use of von Neumann entropy is proposed as a method for the determination of the energy of a resonance.
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We investigate coherent single-microwave-photon transport in the coupled superconducting transmission lines coupled to superconducting quantum interference device based charge qubits. The Fano resonance can be observed in the scat...
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We investigate coherent single-microwave-photon transport in the coupled superconducting transmission lines coupled to superconducting quantum interference device based charge qubits. The Fano resonance can be observed in the scattering spectra in both the linear and nonlinear regimes of the dispersion relation of the microwave photon.We further find that the degree of the two-qubit entanglement can vary from unity to zero when the Fano resonance occurs. There exists a correspondence between the entanglement and the Fano resonance.
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A core-resonance cylindrical whispering gallery mode (WGM) laser is reported in dye-doped nematic liquid crys- tals (NLCs) filled in a glass capillary. This laser runs on the basis of the properties that NLC has an extraordinary r...
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A core-resonance cylindrical whispering gallery mode (WGM) laser is reported in dye-doped nematic liquid crys- tals (NLCs) filled in a glass capillary. This laser runs on the basis of the properties that NLC has an extraordinary refractive index much higher than that of a glass and that it plays as a good solvent for laser dye. The conditions of the WGM lasing are investigated on the basis of gain and loss of the core medium. The NLC is a material suitable for optofluidic core-resonance cylindrical WGM lasers, which are promising, from an application viewpoint, for biodevices or analytical microdevices.
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It is generally believed that automatic gain control is necessary for making an oscillator stable against both voltage supply and temperature variations. First, we show that automatic gain control is, at least, questionable if low...
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It is generally believed that automatic gain control is necessary for making an oscillator stable against both voltage supply and temperature variations. First, we show that automatic gain control is, at least, questionable if low Q resonators must be used. Afterwards, we demonstrate that virtually perfect stability against voltage supply variations may be easily achieved by a proper biasing strategy. Finally we introduce the PTAT oscillators, which allow to improve stability versus temperature variations without automatic gain control.
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