Abstract
We consider axion cloud decay due to the axion-photon conversion with multi-pole
background magnetic fields. We focus on the
ℓ
=
m
= 1 and
n
= 2 mode for the axion field
configuration since ...it has the largest growth rate associated with superradiant instability.
Under the existence of a background multi-pole magnetic field, the axion field can be converted
into the electromagnetic field through the axion-photon coupling. Then the decay rate due to the
dissipation of the converted photons is calculated in a successive approximation. We found that
the decay rate is significantly dependent on the azimuthal quantum number characterizing the
background magnetic field, and can be comparable to or larger than the growth rate of the
superradiant instability.
This paper presents an investigation of wire electrical discharge machining (WEDM) of new fabricated aluminium base composite with 5% graphite by weight, i.e., Al/Gr/Cp5. The new fabricated metal ...matrix composite (MMC) has a complete application in space, defence, automobile, and other concerned metal industries. In this work, adaptive neuro-fuzzy inference system (ANFIS) and the response surface method (RSM) were selected for the analysis and modelling purposes. ANFIS is a soft computing technique used in nonlinear data training. Taguchi's L
27
plan was employed to conduct the experiments. The process parameters such as pulse-on time (PON), pulse-off time (POFF), a feed rate of wire (FRW) and the input current (IC) were selected for the experimentation. Based on the experimental findings, PON is identified as the most dominant parameter and the input current. WEDM performance was measured in terms of surface roughness (SR). For the optimised (minimum) surface roughness of 1.8625 microns, the best set of process parameters was PON (108 μs), POFF (52 μs), FRW (4 m/min) and the input current (12 Amp). ANFIS-predicted results were compared with the experimental results. An acceptable agreement is observed with the high value of the correlation coefficient (R
2
= 0.9624). The soft computing technique, like ANFIS-RSM, shows a good competency and reliability for the presented work.
The abundance of organic pollutants in environment has persuaded researchers to establish an advanced technology and address this global issue. We discovered that graphene incorporated p-type ...CuO/n-type TZB-Gr (Copper Oxide/Titanium dioxide-Zinc Oxide-Bismuth Oxide-Graphene) heterojunctions nanofibers (NFs) with band gap of (1.7eV) can effectively produce active radicals to degrade most of the organic pollutant to become CO2 and H2O. One-dimensional electrospun (NFs) of p-type CuO/n-type TZB-Gr heterojunctions with high visible and UV-light activity were successfully synthesized using sol-gel and a facile electrospinning technique. The results show that the CuO/TZB-Gr (NFs) were 75 nm in diameter and multi-micrometers in length. The as prepared electrospun (NFs) were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), UV–vis diffuse reflectance (DR) spectroscopy, resonant Raman spectroscopy and thermogravimetric analysis (TGA). Kinetic study of composite CuO/TZB-Gr (NFs) was carried out. Compared with commercial P25 particles, the as prepared p-type CuO/n-type TZB-Gr (NFs) disclosed a strikingly higher photocatalytic activity in the degradation of Methylene Blue (MB) and formaldehyde. The enhanced photocatalytic activity of MB under Visible and UV light and formaldehyde under Visible light could be regarded to the formed p–n heterojunction between CuO and TZB-Gr and their higher separation efficiency of photogenerated electrons and holes. Moreover, due to one–dimensional nature of p-type CuO/n-type TZB-Gr heterojunctions, these (NFs) could be easily reused without the decrease of photocatalytic efficiency, therefore rendering a novel strategy for environmental applications.
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•Electrospun p-Type CuO/n-Type TZB-Gr Heterojunction nanofibers (NFs) have been reported.•These Heterojunction (NFs) have low band gap, reduced charge recombination and greater charge separation.•Degradation of Organic dye Methylene Blue and formaldehyde is reported.•Heterojunction (NFs) exhibited a higher degradation rate (k) than commercial TiO2 P25 nanoparticles.•Catalytic mechanism of the p-Type CuO/n-Type TZB-Gr Heterojunction (NFs) was proposed.
Test of the no-hair theorem is the primary target with gravitational waves from binary black holes. In this paper, we analyze gravitational-wave data from the LIGO-Virgo-KAGRA detection of binary ...black-hole mergers using the ΨFD model, which is a non-general relativity full waveform template for arbitrary axisymmetric black holes. By analyzing two high signal-noise-ratio events, GW150914 and GW200129_065458, the no-hair theorem is tested at a significance level of 95%, which is the best constraint until now. More events and further analysis are needed to investigate the suspected deviation from the Kerr scenario found in the special event.
Abstract Scalar-tensor theories have taken on a key role in attempts to confront the growing open questions in standard cosmology. It is important to understand entirely their dynamics at ...perturbative level including any possible spatial dependence in their growth of large scale structures. In this work, we investigate the spatial dependence of the growth rate of scalar-tensor theories through the Mészáros equation. We confirm that at subhorizon level this dependence does not play a major role for viable models. However, we establish conditions on which this criterion is met which may be important for developing new models. In our work, we consider three specific models that exhibit spatial dependence of the growth rate at subhorizon modes, which may also be important for early Universe models.
Abstract
We present a novel method that solves Teukolsky equations with the source to calculate radiation fluxes at infinity and event horizon for any perturbation fields of type-D black holes. For ...the first time, we use the confluent Heun function to obtain the exact solutions of ingoing and outgoing waves for the Teukolsky equation. This benefits from our derivation of the asymptotic analytic expression of the confluent Heun function at infinity. It is interesting to note that these exact solutions are not subject to any constraints, such as low-frequency and weak-field. To illustrate the correctness, we apply these exact solutions to calculate the gravitational, electromagnetic, and scalar radiations emitted by a particle in circular orbits around a Schwarzschild black hole. Numerical results show that the proposed exact solution appreciably improves the computational accuracy and efficiency compared with the 23rd post-Newtonian order expansion and the Mano-Suzuki-Takasugi method.
In view of the difficult selection of ozone treatment process and treatment conditions in the degradation of acid red GR and reactive red X-3B dye wastewater, six different treatment methods were ...used to treat the wastewater in the experiment, including ozone treatment alone, ozone-coupled micro-electrolysis, ozone-coupled hydrogen peroxide, ozone-coupled ultraviolet (UV), ozone-coupled ultrasonic, metal-catalytic ozone-oxidation treatment. The treatment conditions of the six processes were optimized and the treatment effects of the six processes were compared. The results show that when treating acid red GR dye wastewater, ozone treatment alone has the best removal effect. The chroma removal rate can reach 99.99% after 30min treatment, and the COD removal rate can reach 69.41% after 90 min treatment. When treating reactive red X-3B dye wastewater, ozone-coupled UV oxygen treatment has the best removal effect. The chroma removal rate can reach 99.23% after 30 min treatment, and the COD removal rate can reach
Introdução – A preservação a longo prazo de lâminas de citologia aspirativa por agulha fina (CAAF) é um requisito essencial nos laboratórios de citopatologia para a posterior realização de ...imunocitoquímica (ICQ). A ICQ contribui para um diagnóstico correto e completo, sendo essencial a preservação morfológica e antigénica a longo prazo para obter resultados confiáveis. Neste estudo pretende-se avaliar a imunoexpressão dos antigénios TTF1, p40 e cromogranina A em amostras de CAAF do pulmão retiradas do arquivo e coradas pelos métodos de: i) Papanicolaou (Pap) e ii) May-Grünwald Giemsa (MGG); iii) preservadas em polietilenoglicol (PEG); e iv) processadas como citobloco (CB). Métodos – Foram selecionados do arquivo 24 exames de CAAF com diagnóstico de carcinoma primário do pulmão, com amostra processada por cada um dos protocolos em estudo (Pap, MGG, PEG e CB). Com base no diagnóstico foi realizada imunomarcação com anticorpos primários antí-TTF1 (adenocarcinomas), antí-p40 (carcinomas pavimentocelulares) e anti-cromogranina A (carcinomas neuroendócrinos). A qualidade da imunomarcação foi aferida por dois avaliadores independentes com recurso a uma escala, com classificação entre 0 e 27 pontos, e que compreende os parâmetros: preservação morfológica, intensidade da marcação específica, sensibilidade, especificidade e contraste. Resultados – A pontuação média obtida para os métodos Pap, MGG, PEG e CB foi de 21,58 (±4,54), 11,79 (±1,88), 22,25 (±5,30), 26,31 (±1,21) pontos, respetivamente. O CB conseguiu resultados superiores aos restantes protocolos em estudo (p<0,05). Quando comparados os protocolos a par (post-hoc de Tuckey), os únicos que não apresentaram diferenças estatisticamente significativas entre si foram Pap e PEG (p=0,814). Conclusões – O CB é o protocolo de eleição para a realização de ICQ nas amostras e para os antigénios em estudo. Os métodos Pap e PEG apresentaram perda de imunormarcação, podendo levar a resultados falso-negativos. O protocolo de MGG não obteve imunomarcação em nenhuma amostra.
Abstract
Stationary compact astrophysical objects such as black holes and neutron stars behave as classical systems from the gravitational point of view. Their (observable) curvature is everywhere ...‘small’. Here we investigate whether mergers of such objects, or other strongly dynamical spacetimes such as collapsing configurations, may probe the strong-curvature regime of general relativity. Our results indicate that dynamical black hole spacetimes always result in a modest increase
∼
3
in the Kretschmann scalar, relative to the stationary state. In contrast, we find that the Kretschmann scalar can dynamically increase by orders of magnitude, during the gravitational collapse of scalar fields, and that the (normalized) peak curvature does
not
correspond to that of the critical solution. Nevertheless, without fine tuning of initial data, this increase lies far below that needed to render quantum-gravity corrections important.
