Interference Phase Research Articles

Study Coordination Design of Over Current Relay on The Kiln Area Electrical System

PT. Semen Padang is one of the largest cement producers in western Indonesia, along with the development of the cement industry PT. Semen Padang added a new Indarung VI factory to support the production process to meet market demand. With the addition of this new factory, a good safety design is needed in the design of the electrical system so that production continuity is not disturbed and reliability values are high. Therefore, over-current protection coordination studies are needed on the electrical system of the kiln area at Trafo 2 Indarung VI PT. Semen Padang to get a safe and reliable system. In the final task, this time will be done modeling, simulation of load flow and short circuit, calculation of relay settings, and simulation of coordination of overcurrent protection phase interference in the electrical system kiln area in Transformer 2 Factory Indarung VI PT. Semen Padang. The plot results of the coordination of the time flow curve obtained through the results of analysis and manual calculations recommended tuning pick-up overcurrent relayand grading time overcurrent relaytuning phase interference. Grading time between overcurrent relay is coordinated by 0.2 seconds. With the protection coordination setting, the electrical system of the kiln area at the Indarung VI factory PT. Semen Padang is safer and more reliable.

Phase Enabled Circular Dichroism Reversal in Twisted Bi‐Chiral Propeller Metamolecule Arrays

AbstractArtificial chiral structures play a crucial role in the realization of strong chiroptical responses and flexible light manipulation. Here, a unique bi‐chiral propeller metamolecule array is demonstrated in which the geometric chirality of the subunit with intracellular blades is opposite to that of the subunit with intercellular blades. Benefited from the special propeller twists, it is demonstrated that the propeller metamolecule arrays support the phase controlled chiral surface lattice resonances, whose amplitude can be tailored by tuning the coupling of chiral centers to change the interference phase. Specifically, the circular dichroism of the metamolecule array is readily reversed by rotating the propeller blades without changing the local geometry and the lattice parameters. The proposed bi‐chiral propeller metamolecule array and the exotic circular dichroism reversal are further demonstrated in experiments by adopting a nano‐kirigami fabrication method. This work provides a novel paradigm to investigate the profound chiroptical responses and manipulate the advanced spin states of light.

Nonlinear response of a premixed low-swirl flame to acoustic excitation with large amplitude

This paper describes an experimental investigation of the nonlinear response of a premixed methane/air low-swirl flame to imposed acoustic excitation with perturbation amplitude up to 95% of the bulk velocity. Amplitude dependence of flame dynamic at a low frequency,75 Hz, and a high frequency, 195 Hz, over a wide range of excitation level is analyzed in detail. Proper orthogonal decomposition is used to identify the dominant structures in the low-swirl flame. Experimental results show the gain of FDF of the low-swirl flame has a peak value at 65 Hz and a local minimum at 105 Hz which is caused by the destructive (out of phase) and constructive (in phase) interference of the axial and azimuthal velocity fluctuations. The low-swirl flame shows complex nonlinear amplitude dependence which depends on the excitation frequency. Flame harmonic response has a close relation with non-linearity behavior. Vortices are formed and convected downstream along the flame approximately at bulk flow velocity, inducing flame rollup and shear layer instabilities. Fluctuation of heat release rate in the flame tail region and shear layer due to the combined impact of flame rollup and shear layer instabilities govern the flame nonlinear response. Further POD analysis shows the most energetic modes (mode 1 and mode 2) feature symmetric wave-like structures. As the perturbation level increases, the higher anti-symmetric and helical modes are inhibited.

Sources of infestation of the rice sheath mite, Steneotarsonemus spinki Smiley (Acari: Tarsonemidae), in West Bengal, India

The Rice Sheath Mite, Steneotarsonemus spinki Smiley (Acari: Tarsonemidae) is a pest of Kharif Rice (wet rice) of West Bengal, causing losses every year. It initially infests leaf sheaths, moving later onto the grains. It is not known how the mite survives in the off season, which is important for devising management strategies. The present investigation was conducted to find out the sources of infestation of S. spinki. It was concentrated on four types of substrates: rice associated weeds, soil, rice grains of different ages (before and after harvesting) and rice stubbles. Mites detected in any of those possible sources were slide mounted in modified Berlese medium and examined under phase and differential interference contrast microscope for identification. Tarsonemid mites were found on some grassy weeds, but not Steneotarsonemus spinki Smiley. No tarsonemid mite was found in soil samples from infested fields. Steneotarsonemus spinki was found on rice grains of different ages and in stubbles. Hence, both rice grains and rice stubbles could be important sources of infestation of S. spinki to new plants at each season.

Non-invasive deformation metrology using subspace analysis in digital holographic interferometry

For non-invasive precision measurement of deformation using digital holographic interferometry (DHI), reliable estimation of interference phase from complex fringe signal is required. This article introduces a method for estimation of interference phase in DHI. The proposed method is based on computing roots of a frequency estimation function obtained from noise subspace of the fringe signal. The main advantage of the proposed method is robustness against severe noise. In addition, the method also offers the capability of direct phase derivative estimation. The performance of the proposed method is validated using numerical simulations. Our simulation results show that even for signal to noise ratio as low as −5 dB, the proposed method offers root mean square errors of less than 1 radian for phase retrieval. The practical utility of the method for non-invasive deformation analysis is demonstrated using experimental results in DHI.

Artificial Propeller Chirality and Counterintuitive Reversal of Circular Dichroism in Twisted Meta-molecules.

Here we demonstrate an optical propeller chirality in artificially twisted meta-molecules, which is remarkably different from conventional optical helical chirality. Giant circular dichroism (CD) is realized in a single layer of meta-molecule array by utilizing the surface lattice resonances that are formed by the coupling of chiral electric quadrupole modes to the diffractive lattice mode. Due to the special twist of the propeller blades, the periodic meta-molecule array is hybridized by unit cells with two different chiral centers. As a result, the CD response is readily reversed by tailoring the interference phase through engineering the structural blades without inverting the geometric chirality. Importantly, the enhanced CD and its sign reversal are demonstrated in experiments by using a nano-kirigami fabrication technique.

Phase interference for probing topological fractional charge in a BiSbTeSe2-based Josephson junction array

Fractional charges can be induced by magnetic fluxes at the interface between a topological insulator (TI) and a type-II superconductor due to axion electrodynamics. In a Josephson junction array with a hole in the middle, these electronic states can have phase interference in an applied magnetic field with period, in addition to the 2π interference of the Cooper pairs. Here, we test an experimental configuration for probing the fractional charge and report the observation of phase interference effect in superconducting arrays with a hole in the middle in both Au- and TI-based devices. Our numerical simulations based on resistive shunted capacitive junction model are in good agreement with the experimental results. However, no clear sign of an axion charge-related interference effect was observed. We will discuss possible reasons and perspectives for future experiments.

Three-Dimensional Surface Reconstruction of Space Targets Using a Terahertz MIMO Linear Array Based on Multilayer Wideband Frequency Interferometry Techniques

In this article, the three-dimensional (3-D) surface reconstruction techniques of space targets were studied with a multiple-input-multiple-output (MIMO) linear array in the terahertz band. Conventional wavenumber domain integration-based reconstruction algorithm is unable to accurately reconstruct the continuous surfaces owing to the fixed step length in the range direction. To overcome this shortcoming, a phase unwrapping-free multilayer wideband frequency interferometry algorithm (MWFIA) was proposed. The MWFIA divides the targets into several layers based on the range resolution corresponding to the bandwidth of interference phase images, which can achieve surface reconstruction of targets with arbitrary varying range of distance. Besides, to ensure a satisfactory reconstruction accuracy under low signal-to-noise ratio environments, the interference phase errors introduced by noise are greatly suppressed by performing interference phase extraction between wideband two-dimensional imaging results of adjacent center frequency points. Both simulation and experimental results in the 0.22 THz band were provided to demonstrate the performance of the proposed method in comparison with those of the wavenumber domain integration-based and the previous frequency interferometry-based surface reconstruction techniques.

Temporal and Spatial Development of the EM Field in a Shielding Enclosure with Aperture after Transient Interference Caused by a Subnanosecond High-Energy EM Plane Wave Pulse

A proper assessment of the shielding effectiveness of an enclosure with aperture under subnanosecond transient interference requires a better understanding of the coupling and development mechanisms of the EM field induced inside the enclosure. In this paper, the results of a numerical study of the temporal and spatial development of the electromagnetic (EM) field in a shielding enclosure with aperture after transient interference caused by a subnanosecond high-energy EM plane wave pulse are presented. The interference pulse had Gaussian distribution of the electric and magnetic fields with amplitudes of 106 V/m and 2.68·103 A/m, respectively. The maximum pulse power density was 2.68 GW/m2. The novelty of this study was 2D and 3D images, which visualized the temporal and spatial build-up of electric and magnetic fields in the shielding enclosure within 90 ns after the transient interference. This is 58 times longer than the time needed by any EM wave to travel the distance between the front and rear walls of the enclosure. The presented images, showing the EM field morphology over a relatively long period of time, were crucial for understanding the EM field build-up process inside the shielding enclosure with aperture. They revealed the existence of two unknown phases of the EM field build-up in the enclosure with aperture. We call these two phases the wave phase and the interference phase. In the wave phase, the EM field is generated in the form of so-called primary and secondary wave pulses, traveling towards the enclosure rear wall. In the interference phase, the EM field has the form of temporally and spatially varying pulse-like interference (size-limited) patterns of the associated electric and magnetic fields. The EM field induced in the enclosure is long-lasting compared to the interference pulse duration. The amplitudes of the electric and magnetic fields decreased about threefold in 5 ns and 30-fold in 90 ns, thus exhibiting a severe EM hazard for much longer than the external interference duration. For a long period of time, the highest EM field amplitudes would change their locations in the enclosure, which makes it difficult to assess the shielding effectiveness on the basis of classical definitions. The existence of the long-lasting temporally and spatially varying EM field induced in the enclosure with aperture by the subnanosecond transient interference, visualized in detail in this paper, confirms that a new definition and measurement methods of shielding effectiveness under transient conditions are needed. The obtained results provide a source of data that can be useful when working on the introduction of time-domain parameters to evaluate the transient shielding effectiveness in the case of the ultrashort EM interference.

Speckle phase map denoising based on empirical wavelet transform and cross correlation

In order to resolve the problem of speckle interference phase map noise interference, a phase denoising method of digital speckle pattern interferometry based on empirical wavelet transform (EWT) and cross correlation is proposed. First, the EWT is used to decompose the speckle phase map, and a series of components is obtained. Then the noise-free components containing phase information are extracted based on the cross correlation. After that, combined with the particle swarm optimization algorithm and sine–cosine denoising method, an improved sine–cosine denoising method is proposed to process the noise components. Finally, the noiseless components are reconstructed to obtain the denoised speckle phase map. Simulation and experimental results show that the proposed method can effectively reduce the noise interference and obtain accurate phase information.

(Invited) The Quantum Phase Interference in the Excited Triplet of Fullerene

High spin magnetic molecules are promising candidates for quantum information processing because their intrinsic multiplicity facilitates information storage and computational operations. However, due to the absence of suitable sublevel splittings, their susceptibility to environmental disturbances and limitation from the selection rule, the arbitrary control of the quantum state of a molecular electron multiplet has not been realized. Here we exploit the photoexcited triplet of C70 as a molecular electron spin qutrit with pulsed electron paramagnetic resonance. We prepared the system into 3-level superposition states characteristic of a qutrit and validated them by the tomography of their density matrices. To further elucidate the coherence of the operation and the nature of the system as a qutrit, we demonstrated the quantum phase interference in the superposition. The interference pattern is further interpreted as a map of possible evolution paths in the space of phase factors, representing the quantum nature of the 3-level system. Figure 1

Resonant control of photoelectron directionality by interfering one- and two-photon pathways

Coherent control of interfering one- and two-photon processes has for decades been the subject of research to achieve the redirection of photocurrent. The present study develops two-pathway coherent control of ground state helium atom above-threshold photoionization for energies up to the $N=2$ threshold, based on a multichannel quantum defect and R-matrix calculation. Three parameters are controlled in our treatment: the optical interference phase $\Delta\Phi$, the reduced electric field strength $\chi=\mathcal{E}_{\omega}^2/{\mathcal{E}_{2\omega}}$, and the final state energy $\epsilon$. A small energy change near a resonance is shown to flip the emission direction of photoelectrons with high efficiency, through an example where $90\%$ of photoelectrons whose energy is near the $2p^2\ ^1S^e$ resonance flip their emission direction. However, the large fraction of photoelectrons ionized at the intermediate state energy, which are not influenced by the optical control, make this control scheme challenging to realize experimentally.

Optical multiple-image authentication and encryption based on phase retrieval and interference with sparsity constraints

An optical multiple-image authentication and encryption method based on phase retrieval algorithm (PRA) in the Fresnel domain and interference with sparsity constraints is proposed. In our proposed method, sparse phase and space multiplexing technique are respectively introduced to authentication and encryption for multiple-image. Each target image is respectively encrypted into two phase-only masks, which contain the phase data generated from three binary images by applying PRA in the Fresnel domain and need to be verified before used for decryption. That the target images are respectively reconstructed by using different decryption keys in the proposed method increases the security of the cryptosystem. Numerical simulation shows that the proposed method has high multiplexing capacity and security.

Development of One-dimensional Magnonic Crystal using Forward Volume Spin Wave

Spin-wave integrated circuit using magnetic garnet films attract many interests because of their low Joule heating as well as the wide range of tunability of the wavelength. In this circuit, the phase interference of spin waves plays an important role to show functions. Hence, the control of phase and magnitude of spin waves is an essential technique to realize spin-wave integrated circuits. To control the phase and magnitude of spin waves, we fabricated magnonic crystals using metal periodic structures fabricated on magnetic garnet films. Forward volume spin waves propagated through the magnonic crystal and showed a magnonic bandgap. In this paper, the designing of the magnonic crystal using finite integration technique (FIT) and fabrication of samples using etching were also described.

On the noise reduction of a porous trailing edge applied to an airfoil at lifting condition

Numerical simulations, using a lattice-Boltzmann technique, have been carried out to study the effect of aerodynamic loading and Reynolds number on the aeroacoustics of a porous trailing-edge insert. The airfoil is a National Advisory Committee for Aeronautics 0018 with the last 20% of its chord being replaceable with porous insert based on a Ni-Cr-Al metal foam with a mean pore diameter of 0.8 mm. The porous insert is modeled as an equivalent fluid region governed by the Darcy's law. The angle-of-attack is set to 7.8°, and the freestream Reynolds numbers based on the airfoil chord are 2.7 × 105 and 5.4 × 105. The amount of noise reduction produced by the porous insert generally decreases as the angle-of-attack or Reynolds number is increased, although the far-field noise directivity remains similar to that of the solid insert case. Unlike for a solid insert, in which noise sources are concentrated at the trailing edge, those on the porous insert are distributed across the porous medium surface, and they promote phase interference effect that causes noise attenuation. This mechanism is realized by the pressure release process, which refers to the interaction between surface pressure fluctuations on both sides of the trailing edge through the porous medium. It is found that the pressure release process is strongly present at the last 25% of the porous insert extent, and thus the upstream segment plays a relatively limited role in noise attenuation. The porous insert also causes velocity deficit, enhanced Reynolds shear stress, and lower convection velocity in the turbulent boundary layer. Nevertheless, since only the flow field surrounding the porous insert is affected, the overall aerodynamic penalty is relatively minor. It has also been found that the effect of mean cross-flow inside the porous medium is almost negligible in the present investigation due to the small surface pressure difference between the two sides of the porous insert.

Analytical representation for amplitudes and differential cross section of pp elastic scattering at 13\xa0TeV

With analytical representation for the pp scattering amplitudes introduced and tested at lower energies, a description of high precision is given of the dsigma /dt data at sqrt{s}= 13 TeV for all values of the momentum transfer, with explicit identification of the real and imaginary parts. In both t and b coordinates the amplitudes have terms identified as of non-perturbative and perturbative nature, with distinction of their influences in forward and large |t| ranges and in central and peripheral regions respectively. In the forward range, the role of the Coulomb-nuclear interference phase is investigated. The energy dependence of the parameters of the amplitudes are reviewed and updated, revealing a possible emergence of a peculiar behavior of elastic and inelastic profiles in b-space for central collisions, which seems to be enhanced quickly at higher energies. Some other models are also briefly discussed in comparison, including the above mentioned behavior in b-space.

A low noise 8-TDM inline FBG interferometric sensor array for low frequency sensing

An inline time division multiplexed (TDM) fiber Bragg grating (FBG) interferometric sensor array for low frequency bands was presented. The length of the sensing fiber for each element was 58.78 m and the TDM number was 8, both of which are the largest to the best of our knowledge. Besides, in order to pick up phases stably in this ultra-long array with low background noise, a polarization switching (PS) and crosstalk suppressing method was adopted in which a hybrid interference complex synthesis and phase generated carrier (ICS-PGC) algorithm played an important role. A unified demonstration of the ICS-PGC method suitable for 8 or more TDM channels was presented. Experiments showed that even when the PGC modulation frequency was limited to be 6 kHz, the measured noise level could achieve −92 dB@100 Hz, making the system attractive for low frequency sensing applications.

Potential interference immunity of coherent reception of quadruple phase-manipulated radio signal in the presence of coherent harmonic interference

Introduction: The known methods for calculating the interference immunity of radio signal reception in the presence of, for example, harmonic interference, often lead to significantly different numerical values. Each calculation technique of this type has its own algorithm for the resulting formula output, and these conclusions are based on a different level of “engineering rigor”. Purpose: To develop, оn the basis of linear transformation of coordinates, a correct method for calculating the error probability in the correlating reception of a four-fold phase-manipulated radio signal in the presence of coherent harmonic interference. Methods: Four-dimensional probability density of a vector of output voltages of the demodulator correlators in a four-fold integral was represented by a product of one-dimensional probability densities in the space of eigenvectors of the covariance matrix, in which two probability densities are Dirac delta functions. The quadruple integral is brought to double, with new integration limits defined from the plane equations bounding the integration region in this space. Results: Formulas were derived for accurate calculation of average probabilities of symbol and bit errors in coherent reception of a four-fold phase-manipulated radio signal in the presence of coherent harmonic interference. The derived exact formulas were used to plot the dependencies of the average probabilities of symbol and bit errors on the signal-to-noise ratio for the given interference-to-noise ratio and the given interference phase shift relative to the signal phase. It has been studied how the energy ratios of the signal and interference, as well as the interference phase shift, affect the probabilities of symbol and bit errors. It was found that the influence of a non-energy parameter equivalently leads to a change in the energy ratios. Practical relevance: The results of the research can be used in assessing the communication efficiency under interference. The developed technique will allow you to accurately determine the energy characteristics of a radio channel providing the required quality for the reception of transmitted messages in presence of harmonic interference.

Electrophysiological evidence for cross-language interference in foreign-language attrition

Foreign language attrition (FLA) appears to be driven by interference from other, more recently-used languages (Mickan et al., 2020). Here we tracked these interference dynamics electrophysiologically to further our understanding of the underlying processes. Twenty-seven Dutch native speakers learned 70 new Italian words over two days. On a third day, EEG was recorded as they performed naming tasks on half of these words in English and, finally, as their memory for all the Italian words was tested in a picture-naming task. Replicating Mickan et al. recall was slower and tended to be less complete for Italian words that were interfered with (i.e., named in English) than for words that were not. These behavioral interference effects were accompanied by an enhanced frontal N2 and a decreased late positivity (LPC) for interfered compared to not-interfered items. Moreover, interfered items elicited more theta power. We also found an increased N2 during the interference phase for items that participants were later slower to retrieve in Italian. We interpret the N2 and theta effects as markers of interference, in line with the idea that Italian retrieval at final test is hampered by competition from recently practiced English translations. The LPC, in turn, reflects the consequences of interference: the reduced accessibility of interfered Italian labels. Finally, that retrieval ease at final test was related to the degree of interference during previous English retrieval shows that FLA is already set in motion during the interference phase, and hence can be the direct consequence of using other languages.

Coherent manipulation and quantum phase interference in a fullerene-based electron triplet molecular qutrit

High-spin magnetic molecules are promising candidates for quantum information processing because their intrinsic multiplicity facilitates information storage and computational operations. However, due to the absence of suitable sublevel splittings, their susceptibility to environmental disturbances and limitation from the selection rule, the arbitrary control of the quantum state of a molecular electron multiplet has not been realized. Here, we exploit the photoexcited triplet of C70 as a molecular electron spin qutrit with pulsed electron paramagnetic resonance. We prepared the system into 3-level superposition states characteristic of a qutrit and validated them by the tomography of their density matrices. To further elucidate the coherence of the operation and the nature of the system as a qutrit, we demonstrated the quantum phase interference in the superposition. The interference pattern is further interpreted as a map of possible evolution paths in the space of phase factors, representing the quantum nature of the 3-level system.