Phase Modification Research Articles

Non-Kerr constraints using binary black hole inspirals considering phase modifications up to 4 PN order

The gravitational field around an astrophysical black hole (BH) is thought to be described by the Kerr spacetime, which is a solution of the Einstein equation. Signatures of binary black hole (BBH) coalescence in gravitational waves (GW) follow the Kerr spacetime as the theoretical foundation. Hence, any possible deviations from the Kerr spacetime around BHs serve as a test of the nature of gravity in the strong-field regime and of the predictions of General Relativity. In our study, we perform a theory-agnostic test of the Kerr hypothesis using BBH inspirals from the third Gravitational-wave Transient Catalog (GWTC-3). Considering the Johannsen metric, we compute the leading-order deviation to the emitted GW in the frequency domain. Our results provide constraints on two deformation parameters (α13\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha _{13}$$\\end{document} and ϵ3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\epsilon _3$$\\end{document}) and demonstrate the degeneracy between these two non-Kerr parameters.

EXACT SOLUTIONS OF NONLINEAR FRACTIONAL CAHN–ALLEN EQUATION ARIES IN DIFFERENT NONLINEAR PHYSICAL PHENOMENON USING UNIFIED TECHNIQUE

The nonlinear fractional Cahn–Allen (NFCA) equation provides insight into phase modifications and pattern elaboration in natural structures, clarifying how various states of matter have changed throughout time. By using a unified technique, this study aims to present novel, precise solutions to the NFCA problem. This method has led to the discovery of a broad spectrum of soliton solutions, ranging from dark compactons and dark solitons to periodic kink behaviors, rough wave behaviors, and periodic patterns featuring peaked crests and troughs. It has also unveiled anti-kink periodic behaviors, periodic wave behaviors, bright-dark single solitons, periodic patterns displaying anti-peaked crests and anti-troughs, bright solitons, and compound soliton phenomena. Notably, these accomplishments have been made possible through the utilization of Maple software. These findings are important for fractional nonlinear dynamical models (FNLDMs). In order to clarify many dynamic behaviors that solutions of the NFCA equation display in other scientific fields, such as quantum mechanics, mathematical biology, and plasma physics, contour plots and 3D surface representations of these exact solutions are also featured. Through our investigation using the unified technique, we have unveiled a plethora of novel discoveries. Employing this method has revealed a total of 54 fresh findings. In contrast, Javeed et al. [S. Javeed, S. Saif and D. Baleanu, New exact solutions of fractional Cahn–Allen equation and fractional DSW system, Adv. Differential Equations 2018 (2018) 459] applied the first integral technique, resulting in only eight outcomes. Upon comparing their results with ours, our approach has yielded an additional four out of six innovative results. As far as we are aware, the application of our technique to the NFCA equation has not been previously documented. We anticipate that future research will expand this methodology to include other FNLDMs.

FORMING HYDRATE COMPOUNDS SYSTEM 3СaO·Al2O3·3CaSO4·32H2O DURING THE ALUMINATE CEMENT MINERALS HYDRATION

Problem statement. The use of modifying additives and research of their influence on the thermodynamic and hydrodynamic stability of the solidification structure of 3СaOAl2O3·3CaSO432H2O ettringite will lead to an increase in water resistance, improvement of technological factors, which in turn will contribute to the expansion of the scope of application of composites based on such additives. By means of adjusting the water-solid ratio, you can control properties of the initial composite: you can obtain the necessary structure and water resistance. Research of the effect caused by additives on the composites of the CaO–Al2O3–SO3–H2O system and the subsequent development of their compositions will provide an opportunity to control the hydration processes, form highly basic ettringite with the amount of chemically bound water in it reaching 46 %. Purpose of the article – to conduct a research on modification of the ettringite phase aimed at increasing its stability. Conclusions. Stabilization of ettringite composite of optimal composition (70 % of alumina cement and 30 % of gypsum) was determined based on the results of toponymic reactions of transition of the system from the macro-system to the micro- and nanosystem when changing time, by conducting X-ray phase analysis after 3, 7, 14 and 28 days. According to the selected research methodology, semi-aqueous gypsum was modified with alumina cement. Experimentally determined was optimal amount of the modifier (70 % of alumina cement) which is necessary to increase physical and mechanical properties, as well as to form necessary mineralogical composition of the modified binder. During hydration of modified binders based on alumina cement and gypsum, formation of ettringite occurs, which makes it possible to form the necessary structure and basic physical and mechanical properties.

Radio frequency gradient enhanced diffusion-edited semi-solid state NMR spectroscopy for detailed structural characterization of chemically modified hyaluronic acid hydrogels

Applications of functionalized hyaluronic acid (HA) hydrogels for numerous biomedical applications requires their detailed structural characterization. Since these materials are prepared by multistep chemical modifications in the solid phase and not amenable to characterization by standard analytical tools, we employed high-resolution solid-state NMR spectroscopy to gain detailed insights into the structures of the functionalized HA hydrogels. Divinyl sulfone crosslinked HA hydrogels were converted into maleimide-functionalized hydrogels, which were subjected to chemoselective thiol-maleimide reaction using L-cysteine as the protein mimetic thiol reagent. To overcome challenges associated with obtaining high-resolution NMR spectra of crosslinked hydrogels (such as line broadening and overlapping of signals of the hydrogel with those of residual reagents and solvents used during multi-step reaction processes on insoluble polymer matrices), we devised a radio frequency mediated diffusion-edited semi solid-state NMR technique. This technique enabled us to record NMR spectra of hydrogels exclusively by effectively suppressing signals associated with low molecular weight impurities. Thus, it became possible to perform in-depth characterization of these chemically modified HA hydrogels including quantification of reaction outcome for each reaction step.

Modification of BCC phase and the enhanced reversible hydrogen storage properties of Ti-V-Fe-Mn alloys with varied V/Fe ratios

Modification of BCC phase and the enhanced reversible hydrogen storage properties of Ti-V-Fe-Mn alloys with varied V/Fe ratios

Phase Prediction via Crystal Structure Similarity in the Periodic Number Representation.

The periodic number (PN) representation of the chemical systems, introduced by Dmitri Mendeleev, uncovers the fundamental principle of chemical similarity in a straightforward way. In this framework, the rows correspond to the principal quantum numbers of the elements' electronic configurations when considered isolated atoms. This systematic arrangement allows for a deeper understanding of the relationships and patterns among the elements. In this study, we propose a novel strategy for structure type (prototype) prediction by utilizing the PN concept to identify possible modifications and phase stability of unexplored chemical systems. Our PN-based crystal structure prediction (PNcsp) program, which evaluates similarity through PN neighboring in the phase map, provides the most probable prototypes for unknown and unreported modifications of given phases in binary and higher order chemical systems. We applied PNcsp to 59 distinct chemical systems whose equimolar phases are indicated in the respective phase diagrams but lack accurate experimental structure determination. Our methodology identified 93 prototypes for these 59 equiatomic phases, of which 47 exhibit mechanical and dynamic stability. Notably, this approach discovered 19 entirely novel, fully stable polymorphic phases, thereby expanding the known landscape of potential materials. Furthermore, we demonstrated that this method is also effective for nonequimolar and higher order systems.

Differential Effects of Light and Dark Phase Modifications on Jet Lag Adaptability in Mice

ABSTRACTIn chronobiology, shifting light/dark cycles is a common method to disrupt circadian rhythms. While the direction and magnitude of a phase shift (e.g., +6 denoting a 6‐h advanced shift) dictate the temporal change before and after the shift, little attention has been paid to the duration and relative proportion of daytime and nighttime during the shift, leading to a critical, unexamined variable in circadian research. In this study, we introduce the concepts of “L‐shift” (longer light phase on the shift day) and “D‐shift” (longer dark phase), and investigate how these variations impact the adaptability of mice to jet lag. By examining multiple phase shifts (12L vs. 12D, +6L vs. +6D, −6L vs. −6D), we demonstrate that L‐shifts not only facilitate faster adaptation but also significantly reduce the severity of sepsis in a jet lag‐sensitive lipopolysaccharide‐induced sepsis model. Further investigations with additional phase shifts at 1‐h intervals (+8 to +11) reinforced the enhanced fitness of mice under L‐shifts. Mechanistically, L‐shifts were found to increase sleep duration, thereby improving circadian entrainment, with sleep deprivation nullifying the adaptability differences between lighting protocols. These findings underscore a previously unrecognized factor in circadian biology and suggest that optimizing lighting protocols could profoundly improve adaptability to circadian disruptions. This research opens new avenues for enhancing therapeutic strategies and refining experimental designs in the field of chronobiology.

Achieving simultaneous improvement in strength and ductility in Al–Si–Mg–Ce alloy through synergistic morphology modification of eutectic (Si) and Al2Si2Ce phases by Sr addition

In this paper, it was found for the first time that with Sr addition in Al–Si–Mg–Ce alloy, the morphology of eutectic (Si) can be modified from branch to fine fibrous, while the bulk-like Al2Si2Ce phase may replace the elongated needle-like one. Moreover, Mg was observed to segregate along the (Al)/Al2Si2Ce interface and Sr was found to concentrate in the interior of Al2Si2Ce phase. Such heterostructured Sr–Al2Si2Ce was also supported by first-principles calculations. The synergistic morphology modification of eutectic (Si) and Al2Si2Ce phases by Sr addition stimulated the simultaneous improvement in strength and ductility in Al–Si–Mg–Ce alloy.

Cold sintering of α- and γ-modifications of aluminum oxohydroxides: A low-temperature route to porous corundum ceramics

Objectives. To obtain porous corundum ceramics using an innovative cold sintering process starting from different phase modifications of aluminum oxohydroxide — boehmite γ-AlOOH and diaspore α-AlOOH; to study the phase and structural properties of the resulting materials; and to assess their permeability to water.Results. Cold sintering enables the formation of single-phase corundum ceramics with an open porosity of 47.9% directly from the initial boehmite powder with the addition of 5 wt % corundum in the presence of 20 wt % water at a temperature of 450°C, mechanical pressure of 220 MPa, and isothermal exposure for 30 min. Under the same conditions of cold sintering, a mixture of diaspore and boehmite was transformed into α-AlOOH ceramics. This then turned into corundum with an open porosity of 39% when calcined in air at 600°C for 1 h. The resulting materials had permeability for pure water above 5000 L/(m2∙h∙bar).Conclusions. Cold sintering is a promising approach to producing porous corundum ceramics which can be used in filtration systems. Compared to traditional ceramic technology, the new approach reduces energy, time, and labor costs in the material manufacturing. It also eliminates the need to use auxiliary substances (binders, pore-forming agents, etc.).

Atmospheric pressure atomic layer deposition for in-channel surface modification of PDMS microfluidic chips

Polydimethylsiloxane (PDMS) is one of the materials of choice for the fabrication of microfluidic chips. However, its broad application is constrained by its incompatibility with common organic solvents and the absence of surface anchoring groups for surface functionalization. Current solutions involving bulk-, ex-situ surface-, and in-situ liquid phase modifications are limited and practically demanding. In this work, we present a simple, novel strategy to deposit a metal oxide nano-layer on the inside of bonded PDMS microfluidic channels using atmospheric pressure atomic layer deposition (AP-ALD). Using three important classes of microfluidic experiments, i.e., (i) the production of micron-sized particles, (ii) the cultivation of biological cells, and (iii) the photocatalytic degradation in continuous flow chemistry, we demonstrate that the metal oxide nano-layer offers a higher resistance against organic solvent swelling, higher hydrophilicity, and a higher degree of further functionalization of the wall. We demonstrate the versatility of the approach by not only depositing SiOx nano-layers, but also TiOx nano-layers, which in the case of the flow chemistry experiment were further functionalized with gold nanoparticles through the use of AP-ALD. This study demonstrates AP-ALD as a tool to broaden the applicability of PDMS devices.

Empirical approaches for non-linear site response: results for the ESG6-blind test

As a contribution to step 3 of the ESG6 blind prediction exercise, we present an application of two different, purely empirical approaches to estimate the strong ground motion at a soft site ("KUMA") from the observed ground motion at a reference rock site ("SEVO") for the two largest shocks of the Kumamoto 2016 sequence. The two methods estimate the non-linear transfer function between a reference rock and a sedimentary site by modifying the linear transfer function derived from weak motion recordings. The modification is based either on a machine learning tool based on a wide collection of Japanese weak and strong motion recordings and the associated site metadata (method 1), or on an estimate of a site-specific parameter related to an average non-linear site response (method 2). The acceleration time series are then derived at the sedimentary site of interest using an estimation of the time delay between wave arrivals at the rock and site stations, and a minimum phase assumption for the site transfer function. These predictions were made blindly, but after the ESG6 conference they could be compared both with the actual ground motion recorded at KUMA during the two shocks, and the average and range of all other predictions preformed for this benchmark. Both of these purely empirical methods provide an honorable prediction of usual engineering ground motion parameters of the two target events. The performance of these two purely empirical approaches is at least comparable to those of the numerical simulation methods for the foreshock—if not better—and slightly worse for the (largest) mainshock. As the methods required only recordings of weak motions at the target and a referent sites and very simple description of the soil profile. The use of moderate motions to constrain the frequency shift prediction for the second method and the consideration of an alternative phase modification are possible ways to improvement.Graphical

Effect of ultrasonic and mechanical vibration treatments on evolution of Mn-rich phases and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys

Effects of ultrasonic vibration (UV) and mechanical vibration (MV) on the Mn-rich phase modification and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys were investigated. The results show that the UV and UV+MV treatments can significantly refine and fragmentize the microstructures. In addition, UV treatment can significantly passivate the primary Mn-rich Al15Mn3Si2 intermetallics. The formation mechanisms of refinement and passivation of the grains and non-dendrite particles were discussed. Compared with the gravity die-cast alloys, the UV and UV+MV treated alloys exhibit improved tensile and creep resistance at room and elevated temperatures. These results can be attributed to the refinement of the α(Al) grains and the secondary intermetallics, the increased proportion of refined heat-resistant precipitates, and the formation of nano-sized Si particles. The ultimate tensile strength of the UV treated alloys at 350 °C exceeds that of commercial piston alloys. This indicates the high application potential of the developed piston alloys in density diesel engines.

Modification of liquid phase and microstructure of sintered mullite by different additives

AbstractIn the field of ceramics, mullite has drawn plenty of attention due to its low thermal expansion and thermal conductivity as well as its high chemical stability and creep resistance. This work reported the mineral phase, liquid phase, and microstructure evolution of the sintered mullite, using coal‐series kaolin as the raw material and potash feldspar as well as phosphorus pentoxide as additives. The effects of K2O and P2O5 on the content and viscosity of the liquid phase in mullite were calculated using FactSage 8.1. The results showed that the introduction of K2O could inhibit the formation of cristobalite effectively. Adding K2O and P2O5 improved the content of the liquid phase formed during the calcination process. After introducing K2O and P2O5, mullite developed acicular and columnar structures, with average lengths of 9.76 and 7.97 µm, respectively. Furthermore, introducing K2O and P2O5 improved the physical properties of mullite significantly.

Reversible Laser Imprinting of Phase Change Photonic Structures in Integrated Waveguides.

Formation of laser-induced periodic surface structures (LIPSS) is known as a fast and robust method of functionalization of material surfaces. Of particular interest are LIPSS that manifest as periodic modulation of phase state of the material, as it implies reversibility of phase modification that constitute rewritable LIPSS, and recently was demonstrated for chalcogenide phase change materials (PCMs). Due to remarkable properties of chalcogenide PCMs─nonvolatality, prominent optical contrast and ns switching speed─such novel phase change LIPSS hold potential for exciting applications in all-optical tunable photonics. In this work we explore phase change LIPSS formation in thin films of Ge2Sb2Te5 (GST) integrated with planar and rib waveguides. We demonstrate that by fine-tuning laser radiation, the morphology of phase change LIPSS can be controlled, including their period and fill factor, and investigate the limitations of multicycle rewriting of the structures. We also demonstrate the formation of phase change LIPSS on a 1D waveguide, which has potential for use as tunable Bragg filters or structures for on-demand light decoupling into the far-field. The presented concept of applying phase change LIPSS offers a promising approach to enable fast and simple tuning in integrated photonic devices.

Calculating point spread functions: methods, pitfalls, and solutions.

The knowledge of the exact structure of the optical system point spread function (PSF) enables a high-quality image reconstruction in fluorescence microscopy. Accurate PSF models account for the vector nature of light and the phase and amplitude modifications. Most existing real-space-based PSF models fall into a sampling pitfall near the center position, yielding to the violation of energy conservation. In this work, we present a novel, to the best of our knowledge, Fourier-based techniques for computing vector PSF and compare them to the state-of-the-art. Our methods are shown to satisfy the physical condition of the imaging process. They are reproducible, computationally efficient, easy to implement, and easy to modify to represent various imaging modalities.

Modification of the Structure and Mechanical Properties of Cu-30%Zn alloy with Cerium and Silicon

This study investigates how the introduction of cerium and silicon influences the structure and mechanical characteristics of Cu-30%Zn alloy. The examined properties included tensile strength, hardness, and impact resistance. The tensile strength of the developed alloys was determined using an automated JPL tensile strength tester (Model: 130812) with a capacity of 100 kilonewtons, following the ASTM D638 standard. The impact strength was assessed by the ASTM D256 standard using a pendulum impact testing machine (Model: U1820). Additionally, hardness testing was conducted using a Brinell tester. The Brinell hardness test was performed with a portable dynamic hardness tester (Model: DHT-6) by the British Standard (BS EN ISO 6505-1:2014). Specimens were prepared by incorporating cerium and silicon into the Cu-30%Zn alloy at concentrations of 0.1wt%, 0.3wt%, 0.5wt%, 1.0wt%, 3.0wt% 5.0wt% ranging from 0.1% to 5.0%, with increments of 0.2% for micro addition and 2.0% for macro addition. Microstructural analysis was performed using an L2003A reflected light metallurgical microscope. Scanning Electron Microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were also utilized to characterize the cast specimens. The findings revealed a proportional increase in tensile strength, impact strength, and hardness strength with the rise in dopant concentrations up to 3.0wt% for cerium and silicon. Also, the analysis uncovered the presence of. primary α-phase, β-phase (intermetallic phases), and fine stable phase. These phase modifications contributed to the enhancement of mechanical properties. Cu-30wt%Zn enriched with 3.0% cerium and silicon demonstrated heightened tensile strength, impact strength, and hardness, making it a recommended choice for engineering applications.

Synthesis and Catalytic Performance of Bimetallic Oxide-Derived CuO-ZnO Electrocatalysts for CO2 Reduction.

Steering the selectivity of electrocatalysts toward the desired product is crucial in the electrochemical reduction of CO2. A promising approach is the electronic modification of the catalyst's active phase. In this work, we report on the electronic modification effects on CuO-ZnO-derived electrocatalysts synthesized via hydrothermal synthesis. Although the synthesis method yields spatially separated ZnO nanorods and distinct CuO particles, strong restructuring and intimate atomic mixing occur under the reaction conditions. This leads to interactions that have a profound effect on the catalytic performance. Specifically, all of the bimetallic electrodes outperformed the monometallic ones (ZnO and CuO) in terms of activity for CO production. Surprisingly, on the other hand, the presence of ZnO suppresses the formation of ethylene on Cu, while the presence of Cu improves CO production of ZnO. In situ X-ray absorption spectroscopy studies revealed that this catalytic effect is due to enhanced reducibility of ZnO by Cu and stabilization of cationic Cu species by the intimate contact with partially reduced ZnO. This suppresses ethylene formation while favoring the production of H2 and CO on Cu. These results show that using mixed metal oxides with different reducibilities is a promising approach to alter the electronic properties of electrocatalysts (via stabilization of cationic species), thereby tuning the electrocatalytic CO2 reduction reaction performance.

Transformative impact of molybdenum on nickel phosphate hydrate electrodes towards superior energy storage application

Development of high capacity and long cycle life electrode materials is essential to improving energy storage capacity in electrochemical rechargeable devices. In order to be commercially viable, the synthesis of these materials must be straightforward, cost-effective, and ideally a single-step process. We present a binder-free synthesis method for nickel phosphate hydrate (NiPH) and nickel molybdenum phosphate hydrate (NiMoPH) on nickel foam via a simple hydrothermal process. X-ray diffraction (XRD) patterns confirmed the formation of NiPH and NiMoPH phases, while X-ray photoelectron spectroscopy (XPS) verified the presence of nickel (Ni), molybdenum (Mo), phosphorus (P), and oxygen (O) in the composite. Scanning electron microscopy (FE-SEM) revealed the formation of micro-flowers with plate-like structures in NiPH, which transformed into hexagonal rod-like structures upon the introduction of molybdenum in NiPH. This morphological and phase modification increased the charge storage capacity from 1441 mF/cm2 (NiPH) to 2945 mF/cm2 (NiMoPH) at 20 mA/cm2. The NiMoPH electrode demonstrated excellent capacitance retention of 91.8 % over 10,000 cycles. Additionally, asymmetric supercapacitor (ASS) devices were fabricated using NiPH and NiMoPH as positive electrodes and activated carbon (AC) as the negative electrode. The NiPH//AC and NiMoPH//AC configurations exhibited energy densities of 0.086 and 0.201 mWh/cm2, respectively, with the NiMoPH//AC device maintaining about 90 % capacitance retention over 15,000 cycles. This study demonstrates the potential of incorporating conductive transition metals to enhance electrode material performance in energy storage applications.

Test of the Brans–Dicke theory with GW200105 and GW200115

We study whether it is possible to constrain the Brans–Dicke (BD) theory from the measurement of gravitational waves (GW) released in neutron star-black hole collisions. Considering the scalar field modifications through monopole and dipole radiations, we find additional contributions to the phase evolution in the emitted gravitational waveform. After effectively calculating such effect in the post-Newtonian order, we are in a position to measure the scalar field and give bounds on the BD coupling parameter ω BD . We derive the analytical expression for the phase modification due to the orbital eccentricity of eccentric binaries in both general relativity and BD theory. Employing the Bayesian analysis, we obtain the constraints on ω BD from the GW events, GW200105 and GW200115.

Variable Temporal Length Training for Action Recognition CNNs.

Most current deep learning models are suboptimal in terms of the flexibility of their input shape. Usually, computer vision models only work on one fixed shape used during training, otherwise their performance degrades significantly. For video-related tasks, the length of each video (i.e., number of video frames) can vary widely; therefore, sampling of video frames is employed to ensure that every video has the same temporal length. This training method brings about drawbacks in both the training and testing phases. For instance, a universal temporal length can damage the features in longer videos, preventing the model from flexibly adapting to variable lengths for the purposes of on-demand inference. To address this, we propose a simple yet effective training paradigm for 3D convolutional neural networks (3D-CNN) which enables them to process videos with inputs having variable temporal length, i.e., variable length training (VLT). Compared with the standard video training paradigm, our method introduces three extra operations during training: sampling twice, temporal packing, and subvideo-independent 3D convolution. These operations are efficient and can be integrated into any 3D-CNN. In addition, we introduce a consistency loss to regularize the representation space. After training, the model can successfully process video with varying temporal length without any modification in the inference phase. Our experiments on various popular action recognition datasets demonstrate the superior performance of the proposed method compared to conventional training paradigm and other state-of-the-art training paradigms.