Interference Phenomena Research Articles

Dynamics of bubble-shaped Bose–Einstein condensates on two-dimensional cross-section in micro-gravity environment

We investigated the dynamic evolution and interference phenomena of bubble-shaped Bose–Einstein condensates achievable in a micro-gravity environment. Using numerical solutions of the Gross–Pitaevskii equation describing the dynamic evolution of the bubble-shaped Bose–Einstein condensates, we plotted the evolution of the wave function density distribution on its two-dimensional (2D) cross-section and analysed the resulting patterns. We found that changes in the strength of atomic interactions and initial momentum can affect the dynamic evolution of the bubble-shaped Bose–Einstein condensates and their interference fringes. Notably, we have observed that when the initial momentum is sufficiently high, the thickness of the bubble-shaped Bose–Einstein condensate undergoes a counterintuitive thinning, which is a counterintuitive result that requires further investigation. Our findings are poised to advance our comprehension of the physical essence of bubble-shaped Bose–Einstein condensates and to facilitate the development of relevant experiments in micro-gravity environments.

Multi-Target CFAR Detection Method for HF Over-The-Horizon Radar Based on Target Sparse Constraint in Weibull Clutter Background

High frequency radar has a wide monitoring range and low range resolution. It may contain multiple targets or outlier interference phenomena in different clutter regions of the range–Doppler (RD) spectrum in detected background. The key to the performance of target detection in multi target backgrounds is the ability to determine the attributes of targets or outliers. Our previous research shows that the number of targets belongs to an absolute minority compared to the number of background units. In this paper, we propose a new method for multi-target detection building on the ordered statistics constant false alarm detector (OS-CFAR). The new method fully utilizes the sparse characteristics of the target and uses the idea of introducing regularization processing to eliminate interfering targets, and obtain an estimate of shape parameters for target detection. To further improve the performance of the algorithm, a correction method is proposed for the inaccurate selection of the k value. Upon estimating the distribution parameters, the detection threshold is calculated, and the target’s constant false alarm detection is completed. Simulation and measured data show that our algorithm can effectively counter the interference of multiple targets and maintain a constant false alarm characteristic under different conditions, providing a reliable target detection method.

Analysis of Transgenerational Epigenetic Inheritance in C. elegans Using a Fluorescent Reporter and Chromatin Immunoprecipitation (ChIP).

Transgenerational epigenetic inheritance (TEI) allows the transmission of information through the germline without changing the genome sequence, through factors such as non-coding RNAs and chromatin modifications. The phenomenon of RNA interference (RNAi) inheritance in the nematode Caenorhabditis elegans is an effective model to investigate TEI that takes advantage of this model organism's short life cycle, self-propagation, and transparency. In RNAi inheritance, exposure of animals to RNAi leads to gene silencing and altered chromatin signatures at the target locus that persist for multiple generations in the absence of the initial trigger. This protocol describes the analysis of RNAi inheritance in C. elegans using a germline-expressed nuclear green fluorescent protein (GFP) reporter. Reporter silencing is initiated by feeding the animals bacteria expressing double-stranded RNA targeting GFP. At each generation, animals are passaged to maintain synchronized development, and reporter gene silencing is determined by microscopy. At select generations, populations are collected and processed for chromatin immunoprecipitation (ChIP)-quantitative polymerase chain reaction (qPCR) to measure histone modification enrichment at the GFP reporter locus. This protocol for studying RNAi inheritance can be easily modified and combined with other analyses to further investigate TEI factors in small RNA and chromatin pathways.

Острые респираторные инфекции: влияние взаимодействия респираторных вирусов на течение и исходы заболевания

The paper discusses the features of the acute respiratory virus infections’ (ARVIs) etiology, clinical manifestations and therapy, including during the COVID-19 pandemic. The literature analysis has revealed typical trends in the ARVI etiology during the period of SARS-CoV-2 circulation. It has been shown that the rate of major respiratory pathogens decreased sharply during the period of high SARS-CoV-2 activity, while circulation of rhinovirus remained unchanged. This was due to the anti-epidemic measures introduced and the features of interactions between the viruses at the time of the new pandemic strain emergence. The end of the pandemic and the decrease in the SARS-CoV-2 rate during the 2022/2023 epidemic season were associated with the increase in both incidence rate and severity of ARVIs and influenza. Currently, the main reasons for this situation are discussed. These include removal of anti-epidemic restrictions, the decrease in population immunity during the isolation period, and the phenomenon of viral interference between the main pathogens causing ARVIs (rhinovirus, RSV, influenza virus). The article discusses the main directions of the ARVI therapy under current conditions.

Analogy between Boltzmann Machines and Feynman Path Integrals.

Machine learning has had a significant impact on multiple areas of science, technology, health, and computer and information sciences. Through the advent of quantum computing, quantum machine learning has developed as a new and important avenue for the study of complex learning problems. Yet there is substantial debate and uncertainty in regard to the foundations of machine learning. Here, we provide a detailed exposition of the mathematical connections between a general machine learning approach called Boltzmann machines and Feynman's description of quantum and statistical mechanics. In Feynman's description, quantum phenomena arise from an elegant, weighted sum over (or superposition of) paths. Our analysis shows that Boltzmann machines and neural networks have a similar mathematical structure. This allows the interpretation that the hidden layers in Boltzmann machines and neural networks are discrete versions of path elements and allows a path integral interpretation of machine learning similar to that in quantum and statistical mechanics. Since Feynman paths are a natural and elegant depiction of interference phenomena and the superposition principle germane to quantum mechanics, this analysis allows us to interpret the goal in machine learning as finding an appropriate combination of paths, and accumulated path-weights, through a network, that cumulatively captures the correct properties of an x-to-y map for a given mathematical problem. We are forced to conclude that neural networks are naturally related to Feynman path-integrals and hence may present one avenue to be considered as quantum problems. Consequently, we provide general quantum circuit models applicable to both Boltzmann machines and Feynman path integrals.

Magnon Blockade and Magnon–Atom Entanglement Induced by a Qutrit Coupled to a Ferromagnetic YIG Sphere

AbstractHybridized magnonic–photonic systems promise novel applications for future information processing technologies. Here, a hybrid magnonic system comprising of a qutrit (Λ‐type three‐level atom) and a ferromagnetic YIG sphere is considered. Indeed, the whole system is driven by two light fields under the influence of the thermal environment. The indirect magnon–atom interaction is established via the virtual photon exchange. The associated Lindblad master equation is derived and its solution is found to investigate the nonclassical feature, especially in the steady‐state solution. Generally, the system shows considerable nonclassicality, that is, strong magnon antibunching and magnon blockade. In fact, the feasibility of using such a hybrid system to prepare a single‐magnon source based on magnon blockade effects we theoretically demonstrated. Besides, the considered system may be exploited to generate robust and stable magnon–atom entanglement. The appearance of magnon blockade and magnon–atom entanglement in the Λ‐type atom may have its origin in the fact that the atom is trapped in different superposition states, induced by the quantum interference phenomenon. The proposed model and the corresponding results may open up an intriguing prospect to prepare a single‐magnon source and provide further benefits through concatenating with photons in optomagnonic systems.

A method for reducing parasite drag of medium transport helicopter

At present, more and more stringent emission requirements are being imposed on helicopters. Carbon dioxide emissions are a function of fuel consumption, and fuel consumption is directly dependent on the power required for a helicopter cruise flight. The power, required for horizontal flight of a helicopter directly depends on the design of the fuselage and other non-lifting elements, and accordingly, on parasite drag. Therefore, the desire to reduce parasite drag is expected and understandable. Helicopter parasite drag reduction was hailed as one of the key topics of the Seventh Clean Sky Framework Conference. For sixty years of research on this topic, a tremendous amount of experience has been accumulated. In particular, it was found that the main contributors to the total parasite drag of the helicopter were the main rotor hub and swashplate. The subject matter of this article is the study of the parasite drag of the hub and swashplate of a medium passager/transport helicopter Mi-8/17. This study aimed to develop methods to reduce the parasite drag of the Mi-8/17 helicopter. Mi-8/17 is the most mass-produced twin-engine helicopter in the world. Currently, more than 4,5 thousand units are in operation around the world. Therefore, the task of reducing parasite drag for this helicopter is very relevant. Modern methods of computation fluid dynamics (CFD) are used. Modern methods of computational fluid dynamics with an acceptable degree of accuracy make it possible to consider the interference phenomena of the components of the hub, swashplate, and helicopter fuselage, which is not always possible, to obtain correctly during expensive wind tunnel tests. During the work, the following results were obtained. An analysis was made of the contribution of each element of the design of the hub and the main rotor swashplate to the total parasite drag. A method for reducing the parasite drag of a helicopter using a mast fairing is proposed. Several variants of the mast fairing were considered, and the most effective one was chosen. The effect, as well as its degree of influence, of the airflow blown by the fan cooling the air-oil radiators, on the general parasite drag of the helicopter was revealed. The results of the studies, given in this article have been implemented in the production.

Mono- and Bilayer Graphene/Silicon Photodetectors Based on Optical Microcavities Formed by Metallic and Double Silicon-on-Insulator Reflectors: A Theoretical Investigation.

In this work, we theoretically investigate a graphene/silicon Schottky photodetector operating at 1550 nm whose performance is enhanced by interference phenomena occurring inside an innovative Fabry-Pèrot optical microcavity. The structure consists of a hydrogenated amorphous silicon/graphene/crystalline silicon three-layer realized on the top of a double silicon-on-insulator substrate working as a high-reflectivity input mirror. The detection mechanism is based on the internal photoemission effect, and the light-matter interaction is maximized through the concept of confined mode, exploited by embedding the absorbing layer within the photonic structure. The novelty lies in the use of a thick layer of gold as an output reflector. The combination of the amorphous silicon and the metallic mirror is conceived to strongly simplify the manufacturing process by using standard microelectronic technology. Configurations based on both monolayer and bilayer graphene are investigated to optimize the structure in terms of responsivity, bandwidth, and noise-equivalent power. The theoretical results are discussed and compared with the state-of-the-art of similar devices.

Exploring the Possible Phenomenon of Viral Interference Between the Novel Coronavirus and Common Respiratory Viruses.

At the peak of the 2021 wave of the SARS-CoV-2 alpha variant in North America, there was concern for a superimposed wave of viral respiratory infections. There was, however, an apparent shift in the usual epidemiology of these pathogens, especially during the traditional influenza season from approximately October 2020 to March 2021. This article seeks to briefly describe the epidemiology of notable respiratory pathogens during the first wave of the COVID-19 pandemic and to focus on one possible factor for the trends observed. There are many contributory elements to the observed viral trends, but in particular, we present a synopsis of the data supporting the phenomenon of viral interference in relation to the clinically relevant early variants of SARS-CoV-2 (ancestral lineage, alpha, delta, omicron). Viral interference has been implicated in previous pandemics and is currently not well characterized in the setting of the COVID-19 pandemic. It is important to understand this dynamic and its effect on the predominant variants of COVID-19 thus far so that we may appropriately consider its possible influence in patient pathology going forward.

Bandpass Shape of Distortion-Product Otoacoustic Emission Ratio Functions Reflects Cochlear Frequency Tuning in Normal-Hearing Mice

The frequency selectivity of the mammalian auditory system is critical for discriminating complex sounds like speech. This selectivity derives from the sharp tuning of the cochlea’s mechanical response to sound, which is largely attributed to the amplification of cochlear vibrations by outer hair cells (OHCs). Due to its nonlinearity, the amplification process also leads to the generation of distortion products (DPs), some of which propagate out to the ear canal as DP otoacoustic emissions (DPOAEs). However, the insight that these signals provide about the tuned micro- and macro-mechanics underlying their generation remains unclear. Using optical coherence tomography to measure cochlear vibrations in mice, we show that the cochlea’s frequency tuning is reflected in the bandpass shape that is observed in DPOAE amplitudes when the ratio of the two evoking stimulus frequencies is varied (here termed DPOAE “ratio functions”). The tuning sharpness of DPOAE ratio functions and cochlear vibrations co-varied with stimulus level, with a similar quantitative agreement in tuning sharpness observed for both apical and mid-cochlear locations. Measurement of intracochlear DPs revealed that the tuning of the DPOAE ratio functions was not caused by mechanisms that shape DPs locally near where they are generated. Instead, simple model simulations indicate that the bandpass shape is due to a more global wave interference phenomenon. It appears that the filtering of DPOAEs by wave interactions over an extended spatial region allows them to provide a window onto the frequency tuning of single cochlear locations.

Interaxial time-domain interference in single-beam SERF magnetometer

We report the first experimental observation of the interaxial-response-interference in single-beam spin-exchange relaxation-free (SERF) magnetometer. We demonstrate this new form of magneto-optical interaction with atoms, reflected in the time-domain variation of optical signal. Distinguish from the interference phenomenon widely used for sensing, different magnetic-field response rates of multiple axes in atomic sensors will induce frequency-dependent response phase difference, resulting in unexpected signal error. On this basis, we analyze the potential frequency-dependent direction measurement error and abnormal amplitude-frequency response, which enables the pre-estimation of phenomenon when the phase component of external magnetic fields is complex. Orienting to practical applications, we demonstrate the frequency-dependent amplitude error in magnetocardiography (MCG) and propose a method to compensate for the distortion when locating the biomagnetic physiology. A measurement accuracy improvement of 78 % is achieved generally through our method. Our study can be anticipatory extended to various atomic systems, observing and compensating interference-induced measurement error.

Ultrasonic imaging of damage in plates in spectral ripple frequency domain

The ultrasonic C-scan method is a well-known non-destructive inspection method which typically analyzes ultrasound echoes in time domain. Although demonstrated for a variety of defects and materials, it has certain challenges in correctly assessing complex and distributed defects in multi-layer heterogeneous materials, e.g. barely visible impact damage in composite laminates.This paper proposes a C-scan imaging technique in the spectral ripple frequency domain by exploiting interference phenomena between multiple ultrasonic echoes in the response signal. The spectral ripple frequency domain imaging method processes the full A-scan signal without having to define an evaluation time gate. As such, it is highly suited for inspection of curved or tilted parts, or parts having different thickness sections. The method is demonstrated on several 5.5 mm thick carbon fiber reinforced polymer laminates with barely visible impact damage, revealing its capability to resolve neighboring delaminations and small defect fragments over the entire depth of the sample. The spectral ripple frequency domain imaging method shows good performance on datasets with high noise levels and/or low sampling rates, and is computationally very efficient, allowing real-time defect imaging.

The role of local and global preparation in the embodiment of the literary genre’s interference phenomenon in Kurdish novels

Literary genre interference is an important subject to be written about in literary criticism. Throughout this study, the role of local and global preparation in the embodiment of the literary genres interference phenomenon in Kurdish novels has been discussed in detail. Within this study, we refer to local preparation especially the role of the uprising of Kurdish people in 1991 and its impact on literary genre interference. Also, the effect of mass media on novels has been analyzed. The impact of technology and science development, new liberalism, multinational companies, and free markets have shown as part of the global preparation role of literary genre interference which really they have a great impact on the new style of Kurdish novels. In the practical part of this study, some examples of Kurdish novels have been concentrated on; throughout them, the reality of the effects has been proven.

Real-time power quality measurement audit of government building – A case study in compliance with IEEE 1159

Power Quality (PQ) measurements and auditing play a vital role for smart grid applications, industrial safety and reliability. The major electrical PQ characteristics and parameters, like Voltage Sags/Swells, Harmonic Distortion, Voltage Unbalance, Voltage Variation & Flicker, and Supply Interruptions, are studied with the aim of maintaining the international or national standards. The electrical characteristics are studied and analyzed for single-phase and poly-phase systems in this IEEE 1159 recommended practice. The significant PQ constraints and parameters, like electromagnetic interference phenomenon deviation from the regular operation due to load equipment or source to load interaction, are described. Further, it is discussed PQ different monitoring devices, roles, and applications. In this paper, power quality monitoring of the equipment using FLUKE instrument and accessories to identify the equipment performance, audit, PQ issues are discussed practically for a two-panel boards switchgear equipment as a case study in Malaysia. Here, trends in voltage and current changes with current imbalances were observed on 1st May 2019 morning 8'o clock and on 7th May 2019 evening at 9'0 clock.

Permittivity-Asymmetric Quasi-Bound States in the Continuum.

Breaking the in-plane geometric symmetry of dielectric metasurfaces allows us to access a set of electromagnetic states termed symmetry-protected quasi-bound states in the continuum (qBICs). Here we demonstrate that qBICs can also be accessed by a symmetry breaking in the permittivity of the comprising materials. While the physical size of atoms imposes a limit on the lowest achievable geometrical asymmetry, weak permittivity modulations due to carrier doping, and electro-optical Pockels and Kerr effects, usually considered insignificant, open the possibility of infinitesimal permittivity asymmetries for on-demand, dynamically tunable resonances of extremely high quality factors. As a proof-of-principle, we probe the excitation of permittivity-asymmetric qBICs (ε-qBICs) using a prototype Si/TiO2 metasurface, in which the asymmetry in the unit cell is provided by the permittivity contrast of the materials. ε-qBICs are also numerically demonstrated in 1D gratings, where quality-factor enhancement and tailored interference phenomena of qBICs are shown via the interplay of geometrical and permittivity asymmetries.

Cycle kurtosis entropy guided symplectic geometry mode decomposition for detecting faults in rotating machinery

Strong noise interference or compound fault coupling phenomenon may lead to the failure of fault diagnosis technology. This paper focuses on weak feature extraction and compound faults detection for rotating machinery fault diagnosis and proposes adaptive symplectic geometric mode decomposition (SGMD) using cycle kurtosis entropy. Firstly, an index named cycle kurtosis entropy (CKE) is presented to measure the strength of periodic impulses in a signal. The CKE uses the entropy value of calculating all delay cycle kurtosis (CK) to overcome the shortcomings of the CK in adaptive ability and obtain more stable values. Thirdly, CKE is applied to construct an adaptive slip window with optimal length. This process is called the adaptive window segmentation method, which is mainly used to dig out weak fault features in signals. Finally, CKE is used as the component selection criterion to select the components decomposed by SGMD. The selected components are reconstructed to obtain a de-noised signal. Hilbert envelope analysis is applied to the denoised signal to demodulate the fault characteristic frequency. Numerical simulations and experimental investigations using bearings and gears are performed to testify the property of the presented method. The results indicate that the adaptive slip window can enhance the decomposing ability of SGMD under strong noise condition. Moreover, for the strong periodic impulse identification ability, the cycle kurtosis entropy is suitable to determine the optimal components of SGMD. It is expected that the presented method will be effectively used for fault feature extractions in rotating machinery under stationary running conditions.

EXPERIENCE OF USING THE IMMUNE-COMPLEX VACCINE PULVAK MAGNIPLEX IN THE PREVENTION OF INFECTIOUS BURSA DISEASE OF BROILERS

The article presents the results of serological control of the effectiveness of vaccination of broilers against infectious bursal disease (IBD) when the immune-complex vaccine Pulvak MagniPlex is used in the incubator.
 Immune-complex vaccines are vaccines of a new generation, the use of which completely eliminates post-vaccination complications in birds and interference phenomena. The vaccine includes a mixture of specific antibodies and the vaccine strain of the IBH virus. The main property of these vaccines is that when administered subcutaneously in day-old chicks or 18-day-old chicken embryos by the in ovo method, immunity is quickly created even in the presence of high maternal antibodies (MAB). Vaccination in the incubator using immune-complex vaccines is more accurate and provides protection to the whole bird, unlike live vaccines, the main method of which is administration with drinking water. Immuno-complex vaccines are effective even in the presence of high MAT in chickens. Due to this, they provide a much higher level of protection due to the high homogeneity of protective antibodies compared to live attenuated vaccines.
 We present the data of serological monitoring on the average titer of antibodies to the IBH virus in blood sera from 15 batches of broilers aged 45-50 days, which were immunized on the first day in the incubator with the immune-complex vaccine Pulvak MagniPlex. It was established that during a single vaccination in the incubator (15 batches), the Pulvak MagniPlex vaccine stimulates the formation of an active immune response to the IBH virus for the entire period of fattening of broilers. The average titers in the blood sera of broilers aged 45-50 days to the IBH virus ranged from 6,995 to 12,388 after a single vaccination in the incubator (15 batches). The percentage of protective antibodies to the IBH virus in 15 batches of broilers varied from 77.3 to 100, which indicates the intensity of immunity to IBH. A single application of the immune-complex vaccine Pulvak MagniPlex in the incubator stimulates the formation of an active immune response to the IBD virus for the entire period of broiler fattening and provides 100 % protection of 12 batches of broilers and 77.3 % of broilers of 3 batches to IBD. The use of Pulvak MagniPlex allows: to create stable immunity against IBD; to form immunity in each individual broiler, regardless of the level of maternal antibodies; to reduce the impact of stress (compared to mass vaccination in the poultry house by the drinking method. Constant control of the effectiveness of the Pulvak MagniPlex immune-complex vaccine by means of serological monitoring of blood sera in ELISA will allow, depending on the epizootic situation, to timely adjust the vaccination scheme of poultry against IBD.

Ultracompact LiNbO3 ridge waveguide multi-mode interferometer based on low-effective-index mode interference

Waveguides fabricated in crystals, created by utilizing techniques such as ion implantation, femtosecond laser inscription, and proton exchange, have low refractive index contrast with the crystal substrate, which limits their potential development to create compact passive devices, such as waveguide interferometers. In this work, a new waveguide multi-mode interferometer fabrication strategy based on low-effective-index mode interference is presented. Numerical tools have been used for the analysis of this new guided-wave approach used for the device design. The research has demonstrated that a series of high-order modes with an effective refractive index much lower than the substrate can exist in trench-cladded ridge crystal waveguides that have a tiny index contrast in the vertical direction. Simple trench-cladded tapered waveguide configurations to excite such modes and to realize compact waveguide multi-mode interferometers with lengths of several tens and up to hundreds of micrometers are presented. The waveguide multi-mode interferometer design is compact in size, easy to modulate, and with low insertion loss. Furthermore, refractive index sensing is realized, with a sensitivity of ∼490 nm/RIU for aqueous solution samples. The novel multi-mode interference phenomenon present here offers new possibilities and significant opportunities for waveguide modulation and, thus, the development of compact waveguide refractometers.

EFFECTS OF MULTIPATH PROPAGATION CHANNEL IN TIGRIS RIVER

Tigris River is an environment of shallow waters because of its low depth and it has been identified as a multi-path channel. The underwater multi-path propagation leads to reverberation as well as fading, which causes large transmission loss. The present paper conducts 3 underwater acoustic simulation outcomes in the district of Abu Dali - Kazem Al Ali village - Tigris beaches - Baghdad - Iraq. The distance from the sender to the receiver are (100m, 1000 m, and 5000m). With the use Ray model, results have shown that the multi-path propagations dominate in a case where the distance from sender to receiver, has been increased, which resulted in decreasing the grazing angle, thereby, increasing the coefficient of reflection. The consecutive path amplitude values will not be decreased quickly. This is why differences in the time between different paths are minimal. This indicates that the consecutive path-ways will be converged with time, which will result in an inter- symbol interference phenomenon, playing a role in an increase of the received data bit error rate.

Multi-Linguistic Interferences in the Articulation of English Fricatives among Selected Students in a Public University in Lokoja, Nigeria

In the quest to solve human communication problems, the need to learn a foreign language arises, and this usually occurs in a multilingual setting. In the process of this learning, some challenges occur, especially the phonological phenomenon of interference. Given this challenge, the paper contributes to scholarly works on language learning by exploring the articulation of English fricatives by selected [ethnic] students of the Federal University Lokoja (FUL), Lokoja, Nigeria. The researchers carefully selected some participants from the Ebira, Igala and Okun-Yoruba ethnic groups, which form the majority of ethnicities in the university community. A total of 60 students were selected for this study; 20 each from the 3 major ethnic groups in FUL. The major instrument used for this research is the Read Aloud Method, containing nine carefully structured sentences each containing a target English fricative sound. The selected test items were read aloud by the participants and subjected to both perceptual and acoustic analyses. The acoustic analysis was done using the speech analyzer PRAAT. Audio-Articulation Model developed by Mehmet Demirezen was used as the framework for this study. The study reveals that there is a dominant influence from the mother tongue of the participants as they were unable to properly articulate some fricatives in some cases. Also, the study found that there is an overlapping peculiar to the different speakers representing each ethnic group. It can be concluded that since ethnic groups have their distinct languages, it is a factor in the inability of speakers to properly produce fricative sounds. This absence of the fricatives in the L1 shows up in the production of the L2.