Soliton solutions for Hirota–Maxwell–Bloch system and its nonlocal form

This paper studies the Hirota–Maxwell–Bloch (H–MB) system and its nonlocal form. Based on the Darboux Transformations (DTs), for H–MB system, we present general double breathers, what is more, we take appropriate modulation frequency and position parameters to investigate the generative mechanism of rogue wave sequences and different periodic breather sequences. For nonlocal Hirota–Maxwell–Bloch (NH–MB) system, we discuss symmetry preserving and broken soliton solutions under zero background. Besides, we present nine combinations of dark and antidark soliton solutions under continuous waves background when PT-symmetry is broken.

Observation of the Relationship between Ocean Bathymetry and Acoustic Bearing-Time Record Patterns Acquired during a Reverberation Experiment in the Southwestern Continental Margin of the Ulleung Basin, Korea

We observed a distinct drop-off region in the bearing-time record of acoustic reverberation data acquired from the south-western continental margin of the Ulleung Basin, East Sea, in the summer of 2015. 3 kHz continuous waves with pulse lengths of 0.1, 0.3, and 1.0 s were used as source pulses, with an R/V Cheonghae vessel towing a variable depth source and a triplet towed array toward the deep sea from shallow water. The observed pattern changed as the R/V Cheonghae moved across the continental slope further into the sea. This pattern arises as a result of the downward-refracted beams in the 1/2 convergence zone interacting with the soft bottom. In addition, the boundary of the drop-off region was modeled with the two-way maximum travel time of the first bottom-reflected rays using the bathymetry model of the General Bathymetric Chart of the Oceans, 2020. Some discrepancies were observed when comparing the modeled curve to the measured results, and the inaccuracy of the bathymetry model on the continental slope could be the main cause of these discrepancies. This pattern could be useful for bathymetry mapping, as well as estimations of source and receiver configurations.

Successive pandemic waves with more virulent strains, and the effects of vaccination for SARS-CoV-2

Hundred years after the flu pandemic of 1918, the world faces an outbreak of a new severe acute respiratory syndrome, caused by a novel coronavirus. With a high transmissibility, the pandemic spreads worldwide, creating a scenario of devastation in many countries. By the middle of 2021, about 3% of the world population has been infected and more than 4 million people have died. Different from the H1N1 pandemic, which had a deadly wave and cessed, the new disease is maintained by successive waves, mainly produced by new virus variants, and the small number of vaccinated people. In the present work, we create a version of the SIR model with spatial localization of persons, their movements, and taking into account social isolation probabilities. We discuss the effects of virus variants, and the role of vaccination rate in the pandemic dynamics. We show that, unless a global vaccination is implemented, we will have continuous waves of infections.HighlightsThe COVID-19 has infected more than 200 millions and has killed more than 4 million persons.WHO has not been successful in defining a global vaccination policy.Many epidemic scenarios arise when different countries apply different vaccination strategies.Present model can show some insights on how vaccination programs can be managed.

Inhibitory effects of ultrasound irradiation on Staphylococcus epidermidis biofilm

Purpose We aimed to investigate whether low-intensity continuous and pulsed wave ultrasound (US) irradiation can inhibit the formation of Staphylococcus epidermidis biofilms, for potential application in the treatment of catheter-related bloodstream infections (CRBSI). Methods S. epidermidis biofilms that formed on the bottom surfaces of 6-well plates were irradiated on the bottom surface using the sound cell incubator system for different intervals of time. Results US irradiation with continuous waves for 24 h notably inhibited biofilm formation (p < 0.01), but the same US irradiation for 12 h had no remarkable effect. Further, double US irradiation with pulsed waves for 20 min inhibited biofilm formation by 33.6%, nearly two-fold more than single US irradiation, which reduced it by 17.9%. Conclusion US irradiation of a lower intensity (ISATA = 6–29 mW/cm2) than used in a previous study and lower than recommended by the Food and Drug Administration shows potential for preventing CRBSI caused by bacterial biofilms.

High Accuracy Ultrasound Micro-Distance Measurements with PMUTs under Liquid Operation

Ultrasonic systems driven by multi-frequency continuous waves (MFCW) have been used for range distance measurement, offering high accuracy in long and medium range distance estimation. However, the use of continuous waves in very short-distance measurements causes large errors due to multipath reflections. This paper presents a new strategy to estimate very short relative distances with high accuracy based on the use of multi-frequency pulsed waves (MFPW). The proposed strategy allows to avoid the multipath reflections that appear when continuous waves are used, and it improves the achieved accuracy compared to the original MFCW method. To validate it, an 80 µm square AlScN piezoelectric micromachined ultrasonic transducer (PMUT) was chosen as a transmitter while a hydrophone was utilized as a target and receiver, immersed in fluorinert (FC-70) as a propagation medium. Three independent and consecutive tone-burst signals were transmitted successively. The selected frequencies are f1 = 2.3962 MHz, f2 = 2.327 MHz and f3 = 2.1195 MHz, giving first and second-order resolutions of 6.88 and 0.79 µm/°, respectively. Experimental results show a ±6.2 μm measured range error in a range of 3.5 mm, and therefore it represents a good candidate for ultrasound micro-profilometer applications under liquid operation.

Multi-rogue Wave Solutions for a Generalized Integrable Discrete Nonlinear Schrodinger Equation With Higher-order Excitations

In this paper, we construct the discrete rogue wave(RW) solutions for a higher-order or generalized integrable discrete nonlinear Schr¨odinger(NLS) equation. First, based on the modified Lax pair, the discrete version of generalized Darboux transformation are constructed. Second, the dynamical behaviors of first-, second- and third-order RWsolutions are investigated in corresponding to the unique spectral parameter λ, higher-order term coefficient γ, and free constants dk, fk (k = 1, 2, · · · ,N), which exhibit affluent wave structures. The differences between the RW solution of the higher-order discrete NLS equation and that of the Ablowitz-Ladik(AL) equation are illustrated in figures. Moreover, numerical experiments are explored, which demonstrates that strong-interaction RWs are stabler than the weak-interaction RWs. Finally, the modulation instability of continuous waves is studied.

Sobre los inicios de un revisionismo filosófico en Argentina y sus derivas políticas: Homero Guglielmini, Saúl Taborda y Carlos Astrada

This article analyzes the theoretical and ideological interests of the first philosophical essays in Argentina from an intellectual-history perspective. Saúl Taborda (1885-1943), Homero Guglielmini (1903-1968) and Carlos Astrada (1894-1971) had similar theoretical and political trajectories. From the 1920s, when they were in charge of incipient philosophical and avant-garde magazines, they were influenced by the writings of Nietzsche and Sorel. Later, they were interested in German romanticism and Heidegger's work, in the moment when Astrada and Guglielmini became two of the most important intellectuals of Juan Domingo Perón's government. While the so-called historical revisionism has received a remarkable attention, we only have a few works on this philosophical revisionism in Argentina. It is necessary, thus, to differentiate these early revisionist writings from their counterparts dedicated to history. The philosophers did not react to the continuous waves of immigration but rather to liberal political innovations taken as "foreign ideas". They focused especially on the figure of the gaucho and proposed a non-Catholic reading of Hispanicism. In a nutshell, they argued against individualism and forth theoretical tools to think a collective subject. Therefore, this work describes a theoretical trajectory that is well known at the European level, ranging from vitalist and aestheticist irrationalism to nationalist and strongly anti-individualist organisationalist positions.

INVESTIGATING THE STABILITY OF LONG ONE- DIMENSIONAL WAVES IN A SLOPING RUNOFF

The paper is dedicated to the problem of the influence of waves in shallow-water slope flows on the intensity of soil erosion that has not been considered earlier. The stability of one-dimensional continuous waves on the free surface of the sloping runoff is analyzed, both at constant, and with the variable flow along the way. Attention is drawn towards the unsteady flow process and the shape of the free surface in various planes.

Virgo and Gravitational-Wave Computing in Europe

Advanced Virgo is an interferometer for the detection of gravitational waves at the European Gravitational Observatory in Italy. Along with the two Advanced LIGO interferometers in the US, Advanced Virgo is being used to collect data from astrophysical sources such as compact binary coalescences and is currently running the third observational period, collecting gravitational wave event candidates at a rate of more than once per week. Data from the interferometer are processed by running search pipelines for several expected signals, from coalescing compact binaries to continuous waves and burst events. Furthermore, detector characterisation studies are run. Some of the processing needs to be done with low latency, to be able to provide triggers for other observatories and make multi-messenger observations possible. Deep searches are run offline on external computing centres. Thus, data needs also to be reliably and promptly distributed from the EGO site to computer centres in Europe and the US for further analysis and archival storage. Two of the defining characteristics of Virgo computing are the heterogeneity of the activities and the need to interoperate with LIGO. A very wide array of analysis pipelines differing in scientific target, implementation details and running environment assumptions have to be allowed to run ubiquitously and uniformly on dedicated resources and, in perspective, on heterogeneous infrastructures. The current status, possible strategies and outlook of Virgo computing are discussed.

Image Compression Based with Multi Discrete Laguerre Wavelets Transform

The colored image has a large array of numbers that take up a lot of space, creating a problem with transportation and storage, which needs to be urgently solved. It’s essential to find a mathematical tool that shrinks this space when transferring and storing the colored image over the years. Continuous waves such as Fourier and discrete waves such as Haar Symlet 2, coiflet 2, and daubecheis 2 were founded by shrinkage and expansion and characterized with the help of s and r parameters. With the help of the MATLAB program, these basic wavelets installed supplication and image compression, analysis, and lifting procedures. In this study, new waves based on polynomials were discovered, relying on the parent function and through many calculations, clarifying many theories and important features that this wave possesses, such as the orthogonal feature and approach that qualifies these new waves in image processing such as squeeze, jam, and analyze images by searching for a filter. It is suitable and new for carrying out the analysis and reconstruction process with high-pass and low-pass filters resulting from the scaling and wavelet function. Four samples of color images are shown. The compression process was carried out with the help of MATLAB. The use of new waves is Multi Discrete Laguerre Wavelet Transfer, where the standard criteria resulting from the compression process were calculated and the most efficient results were obtained without losing the original information of the image, compared to the standard waves’ tables, which will demonstrate the efficiency of these new wavelets in Multi Discrete Laguerre Wavelet transform.