Analytical Analysis Research Articles

K-means for earthquakes: disaggregation analyses of small events by considering wave components and soil types

In this paper, k-means algorithm has been used to disaggregate seismic parameters to evaluate their inter-correlations. A goal is to quantify in a disaggregated way the weights and effects of each parameter with respect to other ones. From the database, about 4900.0 data, divided into 22.0 categories, have been collected. The main divisions regard the wave components in horizontal and vertical axis and the soil characteristics. The studied seismic zone is the “Norpirenaica oriental,” placed in the Pyrenees area between Spain and France, classified as a very high seismic hazard. Numerical and analytical analyses have been carried out to implement the algorithm. Preliminary analyses and results would quantify the role of the sand horizontal stratigraphy, the non-linear effects, the elasticity of the soil, and the energy damping phenomenon. Curves are plotted in stochastic distributions and elastic spectra accelerations. Results show good prediction for vertical spectral accelerations and for far and relative strong events. Rigorously, results are valid only for the studied seismogenic zone under predefined constrictions and ranges.

Analytical modelling and analysis of the meander-line coil EMATs

The meander-line coil electromagnetic acoustic transducer (EMAT) is widely used in the field of ultrasonic nondestructive testing due to its convenience to generate specific mode of guided waves. Some design methods of the meander-coil EMATs are developed in the frequency-wavenumber domain while others in the time–space domain. In this paper, a unified theoretical framework is developed by proposing an analytical model from the system perspective. Signal transfers between different physical fields in EMAT excitation, wave propagation and EMAT reception are represented as linear time–space-invariant systems. Taking the Rayleigh wave EMAT detection as an example, the analytical model for the transfer functions of these systems is established. The analytical model is experimentally verified by different Rayleigh wave detection techniques: the conventional EMAT, the spatial pulse compression (SPC) EMAT, temporal-spatial pulse compression (TSPC) EMAT and detection cases employing the same receiving EMAT. From the system perspective, the received signal of EMAT is interpreted as the response of the filter system to the input signal. It is found that the meander-coil EMAT can be regarded as the frequency domain expression during the detection. And the frequency domain expression plays different roles in different techniques.

An Analytical Analysis of Mixed Convective MHD Casson Flow with Ramped Wall Temperature

This research discusses the behavior of magnetohydrodynamic Casson fluid subjected to a ramped wall temperature along an infinitely inclined plate. Non-Newtonian fluid, specifically the Casson fluid, is employed to characterize fluid behavior in this research. The effects of porous media, chemical reactions, and radiation are considered. In practical applications, non-Newtonian fluids find use in lubrication such as grease, engine oil, etc. The Laplace transform technique has been applied during this study where ordinary differential equations are converted from the governing partial differential equations with suitable boundary conditions. These transformed dimensionless equations are subsequently solved numerically with Mathematica, and we have achieved the exact solutions of momentum, followed by energy and finally concentration. In the results section, we have analyzed the behavior of flow features under varying conditions of key parameters, including the governing parameters, the unsteadiness parameter, and the Casson parameter. All the results are shown and analyzed in graphs.

Photocatalytic degradation of ampicillin antibiotics in aqueous solution utilizing ZnFe2O4/MWCNTs/TiO2 ternary nanocomposite under solar light irradiation

In this study, a novel photocatalyst composed of zinc ferrite (ZnFe₂O₄), titanium dioxide (TiO₂), and multi-walled carbon nanotubes (MWCNTs) was successfully synthesized via the hydrothermal method, and evaluated for the degradation of ampicillin (AMP) in aqueous solutions. The synthesized nanocomposites were thoroughly characterized using various analytical techniques, including XRD, HR-SEM, HR-TEM, EDX, UV-Vis, FT-IR, BET, and XPS analysis. Crystallite sizes of 24.18 nm for ZnFe₂O₄ and 17.8 nm for TiO₂ were determined. The composite exhibited a band gap of 1.4 eV, indicating its enhanced photocatalytic activity. The photocatalytic performance was assessed under varying conditions, including different nanocomposite dosages (0.3–1 g/L), AMP concentrations (10–50 mg/L), and pH values (2–12). The optimal AMP degradation efficiency of 99.2 % was achieved using 0.7 g/L of the photocatalyst, 10 mg/L of AMP, and a pH of 12 under 90 min of solar irradiation. These optimal parameters were then applied to evaluate AMP degradation using ZnFe2O4, TiO2, and ZnFe2O4/MWCNTs individually, with the degradation rate analyzed using a pseudo-first-order model. The superior photocatalytic efficiency can be primarily attributed to improved charge transfer dynamics and effective electron-hole separation, enabled by the doping of MWCNTs. Hydroxyl radicals (OH•) were identified as the primary reactive species responsible for AMP degradation. Furthermore, the catalyst retained 91 % of its photocatalytic efficiency after eight consecutive cycles, demonstrating excellent stability and reusability. These results underscore the potential of the ZnFe₂O₄/MWCNTs/TiO₂ composite as a highly effective and sustainable photocatalyst for removing pharmaceutical pollutants from aquatic environments.

Gravity-guided snapping sequence in 3D modular multistable metamaterials

The snapping sequence of multistable metamaterials is critical for their applications in elastic wave control and energy release. Despite being a fundamental property, the effect of gravity on the snapping sequence has never been studied. This paper investigates the mechanical mechanism how structural gravity affects the snapping sequence of multistable metamaterials to construct deterministic static and dynamic snapping sequences. A biaxial snap-through availability three-dimensional (3D) modular multistable metamaterial (MMM) is developed. The 3D MMM is assembled from unit cells consisting of a dismountable middle bar (M-bar) and a fixed frame containing two bistable curved beams. Except experimental tests and numerical simulations, analytical analyses are also conducted to verify the snapping sequence induced by gravity in the 3D MMM. In addition, given that the M-bar is dismountable, the effects of its length on the mechanical properties and the impact resistance of the 3D MMM are discussed in detail. It is found that gravity can guide both static and dynamic deterministic snapping sequences of the 3D MMM to optimize the process of elastic wave propagation and energy release, and the proposed 3D MMM can enhance structural impact resistance through elastic deformations.

Analytical parametric analysis of profiled composite walls reinforced with embedded tubes subjected to axial loading

This paper presents analytical analysis of the axial load behavior of a profiled composite wall (PCW) consisting of two profiled steel sheets (PSSs) filled with concrete and reinforced with/without embedded cold-formed steel tubes (CFSTs). This type of composite wall was designed to resist in-plane axial loading (bearing wall). Three experimental samples were tested and its results were presented in this research. The ultimate axial loads of 42 PCW FE models were calculated based on a published work done by the authors earlier. Comparisons between the results of the FE models via the proposed methods and those of Eurocode 4, BS5400, AISC, Hossain (2000), and Wright (1998) were made. Applied calculation formulas for the ultimate axial load were presented via regression analysis theory on the basis of the verified FE results. Comparisons were made between the developed formulas and existing experimental tests, such as those of Hossain (2000) and Wright (1998) and an experimental study performed by the author, and perfect accuracy was achieved. The results of this study proved that the effects of the embedded CFSTs reduced local buckling of the PSS and increased ductility with increasing axial load resistance of the PCW. The provided formulas accurately predict the axial load of the PCWs.

Structural and functional insights into the interaction between the bacteriophage T4 DNA processing proteins gp32 and Dda.

Bacteriophage T4 is a classic model system for studying the mechanisms of DNA processing. A key protein in T4 DNA processing is the gp32 single-stranded DNA-binding protein. gp32 has two key functions: it binds cooperatively to single-stranded DNA (ssDNA) to protect it from nucleases and remove regions of secondary structure, and it recruits proteins to initiate DNA processes including replication and repair. Dda is a T4 helicase recruited by gp32, and we purified and crystallized a gp32-Dda-ssDNA complex. The low-resolution structure revealed how the C-terminus of gp32 engages Dda. Analytical ultracentrifugation analyses were consistent with the crystal structure. An optimal Dda binding peptide from the gp32 C-terminus was identified using surface plasmon resonance. The crystal structure of the Dda-peptide complex was consistent with the corresponding interaction in the gp32-Dda-ssDNA structure. A Dda-dependent DNA unwinding assay supported the structural conclusions and confirmed that the bound gp32 sequesters the ssDNA generated by Dda. The structure of the gp32-Dda-ssDNA complex, together with the known structure of the gp32 body, reveals the entire ssDNA binding surface of gp32. gp32-Dda-ssDNA complexes in the crystal are connected by the N-terminal region of one gp32 binding to an adjacent gp32, and this provides key insights into this interaction.

Self-care strategies used by disaster responders after the 2023 earthquake in Turkey and Syria: a mixed methods study

BackgroundDisaster responders are exposed to several physical and mental health risks. This study aimed to describe self-care strategies used by disaster responders after the earthquake in Syria and eastern Turkey in February 2023.MethodsA study specific web-based questionnaire survey was used to collect quantitative and qualitative data according to a convergent mixed methods approach. Data from 252 disaster responders responding to the earthquakes in Turkey and Syria were analyzed using both descriptive and analytical statistics and summative content analysis of free-text answers. Data were collected in March to July, 2023.ResultsThe most used self-care strategies included resting, social support from colleagues in the field, extra intake of food or drink, and intake of medicines. The recovery strategies varied due to previous disaster response experience, indicating that supportive self-care strategies can be developed or learned.ConclusionGiven the extreme conditions and limited possibilities of external support, sufficient self-care is an essential competence among disaster responders. Self-care strategies can be both external processed such as intake of medicines, social support from others, and internal processes such as personal reflection. Providing oneself with self-care activities seems to be a skill developed with increasing experience supported by pre-deployment training. Therefore, to enhance resilience, self-care strategies should be encompassed in pre-disaster response training.

The impact of receiver arrays on suppressing seismic speckle scattering noise caused by the meter-scale near-surface heterogeneity

Managing seismic scattering noise in geophysical surveying, especially from near-surface heterogeneity, presents significant challenges. We revisit the role of receiver arrays in mitigating such noise in regions with near-surface meter-scale heterogeneity. Moving beyond traditional approaches that focus on suppressing coherent noise from near-surface arrivals and random ambient noise, our research highlights the substantial impact of speckle scattering noise. This noise, resulting from near-ballistic scattering on small-scale heterogeneities, introduces considerable trace-to-trace variability in phase and amplitude, complicating data processing. By integrating a novel model of random multiplicative noise with sophisticated statistical techniques, we determine the efficacy of array stacking in significantly reducing this type of noise and decreasing the dispersion of phase and amplitudes. Our analytical and numerical analyses reveal a notable trend: the reduction in phase and amplitude spread amplifies with the array size. A key finding of our study is the identification of a [Formula: see text] law for phase spread reduction, analogous yet distinct from the well-known [Formula: see text] law observed in amplitude attenuation of additive ambient noise. In our context, this law implies that the standard deviation of residual phase disturbances diminishes in proportion to [Formula: see text], where N denotes the array size. This insight holds particular significance for smaller arrays, such as those with nine receivers commonly used in desert environments.

Analytical model analysis of suspension bridges with tower-girder-connected dampers

Recently the tower-girder-connected damper has been utilized to suppress multi-mode vertical vortex-induced vibration (VIV) of long-span suspension bridges. In this paper, an analytical solution is proposed for the damping ratio of vertical bending modes of a single-span suspension bridge, with a vertical or/and a rotational damper mounted near the end of the stiffening girder, which significantly simplifies the design procedure for tower-girder-connected dampers on suspension bridges. The damping effect and the accuracy of the analytical solution are validated for Humen Bridge. It is found that both the vertical and rotational damper with an appropriate parameter selected can supply significantly additional damping ratio to multiple bending modes of the suspension bridge. The rotational and vertical dampers work in a similar way and provide nearly the same maximum additional damping ratio for each mode. In particular, for the first two symmetric modes, regions of reduced motion near the ends of the stiffening girder are developed due to the effects of cable geometry and elasticity, and this reduces the effect of the tower-girder-connected damper. Excluding these modes, the damper effect on a suspension bridge is similar to that on a tension beam with the same beam stiffness and horizontal tension forces.

Sustainable management of rosemary wastewater and essential oil in agri-environmental bioprocessing

In agriculture, fragrant and medicinal plants offer significant untapped potential for generating biomass-derived materials, particularly from wastewater by-products. In this context, the present study investigates the chemical compositions, antioxidant capacities, antimicrobial properties, acute oral toxicity, and diabetes management potential of wastewater by-products and essential oil from R. tournefortii de Noé. Utilizing advanced analytical techniques, including ATR-FTIR, GC/MS, and HPLC-DAD, were employed to conduct the analyses. ATR-FTIR analysis revealed intricate molecular compositions in both the essential oil and wastewater, confirming terpenoids, phenolic acids, and other functional groups. GC/MS and HPLC-DAD identified dominant compounds in the essential oil, notably camphor (25.49%) and 1,8-cineole (18.03%), while the wastewater contained significant levels of hydroxycinnamic acids such as caffeic acid (23.51%) and rosmarinic acid (21.15%). In terms of bioactivity, the essential oil demonstrated robust antimicrobial effects, with inhibition zones up to 17.1 mm, whereas the wastewater exhibited moderate activity, with zones up to 15.15 mm. Additionally, antioxidant assessments revealed exceptional potency of the wastewater, with IC50 values of 0.046 ± 0.007 mg/mL for DPPH, 0.082 ± 0.013 mg/mL for ABTS, and 2.45 ± 0.71 mg/mL for the beta-carotene/linoleate model system, surpassing the essential oil. Furthermore, both the essential oil and wastewater showed significant inhibitory effects on pancreatic α-amylase, crucial for diabetes management, with wastewater demonstrating remarkable inhibition (IC50 = 0.48 ± 0.021 mg/mL). Acute oral toxicity assessment confirmed the safety of these components, alleviating concerns about potential adverse effects. In summary, these findings highlight the untapped potential and environmental significance of wastewater by-products as valuable resources, positioning R. tournefortii de Noé's essential oil and wastewater as promising agents for sustainable healthcare and environmental sustainability.

Plasmonic Coacervate as a Droplet-Based SERS Platform for Rapid Enrichment and Microanalysis of Hydrophobic Payloads.

A novel and simple coacervate microdroplet-based detection platform for the quantification of trace hydrophobic analytes is presented. Herein, taking advantage of the effective encapsulation and enrichment performance of the condensed coacervates, plasmonic metallic silver nanoparticles (AgNPs) and target hydrophobic analytes are simultaneously concentrated into a single microdroplet. The coencapsulation of AgNPs within coacervates promotes the formation of aggregates with a lot of "hot spots" for surface-enhanced Raman scattering (SERS) enhancement, facilitating the sensitive analysis of hydrophobic analytes by SERS technology. Such plasmonic coacervates are easily prepared and exhibit good reproducibility and signal uniformity. Optimized SERS performance by modulating the volume of encapsulated AgNPs enables quantitative determination of hydrophobic analytes of Nile Red, chlorpyrifos, benzo[e]pyrene, 20 and 50 nm polystyrene nanoplastics with low detection limits of 10-12 M, 10-9 M, 10-10 M, 0.05 ppb, and 0.5 ppb, and an approximately linear correlation between SERS signals and the analytical concentrations. This study opens a new convenient SERS platform for the ultrasensitive detection of hydrophobic hazardous substances, potentially becoming a rapid analysis method for extensive applications ranging from food safety to environment monitoring.

Analytical and dynamical analysis of nonlinear Riemann wave equation in plasma systems

The Riemann wave equation presents appealing nonlinear equations applicable in sea-water and tsunami wave propagation, ion and magneto-sound waves in plasmas, electromagnetic waves in transmission lines, and homogeneous stationary media. This study focuses on deriving soliton solutions in optics and exploring their physical properties. A wave transformation is used to convert a partial differential equation into an ordinary differential equation, from which soliton solutions are obtained using the generalized Riccati equation mapping approach. The solutions encompass various types of solitons, including bright, dark, periodic, and kink solitons. A comparison of solutions from this analytical method enhances the understanding of the nonlinear model’s behavior, with implications in plasma physics, fluid dynamics, optics, and communication technology. Additionally, 2D and 3D graphs illustrate the physical phenomena of the solutions using appropriate constant parameters. The qualitative analysis of the undisturbed planar system involves examining phase portraits in bifurcation theory, followed by introducing an outward force to induce disruption and reveal chaotic phenomena. Chaotic trajectories in the perturbed system are detected through various plots, including 3D, 2D, power spectrum, and chaotic attractor, alongside Lyapunov exponents. Stability analysis under different initial conditions is conducted, and sensitivity assessments are performed using the Runge–Kutta method. The findings are innovative and have not been previously explored for this system, highlighting the reliability, simplicity, and effectiveness of these techniques in analyzing nonlinear models in mathematical physics and engineering.

Comparative effectiveness of endoscopic plantar fasciotomy, needle knife therapy, and conventional painkillers in the treatment of plantar fasciitis: a real-world evidence study

Plantar fascia (PF) is the commonest causes of foot pain in the adult population. Several surgical treatments are available to treat PF. This study was aimed to investigate the clinical efficacy of three different treatments for plantar fasciitis. It was conducted among 60 patients, divided equally into three treatment groups named Needle Knife Therapy, Endoscopic Plantar Fasciotomy, and Conventional Painkillers. Descriptive and analytical analysis were done by using SPSS 25 software. VAS and AOFAS scores were analyzed. The maximum (n = 31) participants were in 41–60 year age range group with normal BMI. These differences of mean VAS and AOFAS pain scores between different treatment groups were statistically significant (One-way ANOVA, p < 0.01). Both scores found lower in the Endoscopic Plantar Fasciotomy group. This study opens a new window of knowledge to achieve sustained pain relief and functional improvement. Moreover, the superiority of Endoscopic Plantar Fasciotomy in treating plantar fasciitis compared to Needle Knife Therapy and Conventional Painkillers was explored.

Design for steel structures deconstruction: an analytics system for construction waste minimization in a circular economy through BIM technology

This study focuses on shifting from traditional demolition methods to more sustainable deconstruction procedures in the steel structures building sector, specifically through Design for Deconstruction (DfD) techniques. The aim is to identify factors for BIM for deconstruction (BIMfD) implementation in Egypt’s construction industry and create a BIM-based Deconstructability Assessment Score (BIM-DAS). A literature review is conducted to determine the design principles for effective building deconstruction, the performance evaluation of DfD, and existing views on BIM implementation. The development of the BIM-DAS & SP includes mathematical modelling rooted in material demand planning. The model was implemented in Building Information Modelling (BIM) environment and it was tested using a case study design. Custom parameters related to deconstruction are added and used in the mathematical model to calculate DAS and salvage performance (SP), followed by a questionnaire and analytical hierarchy process analysis. These findings highlight demountable connections and reusable components as crucial drivers of DfD. Also, the results show that the key variables affecting BIMfD deployment include the availability and acceptance of BIM tools for deconstruction technology among industry professionals, and collaboration between project design and deconstruction teams through integrated platforms. This study demonstrates the usefulness of BIM-DAS and SP as indicators of efficient disassembly of buildings. This study will benefit all stakeholders in designing steel structure deconstruction by providing baseline specifications and a hierarchical model for implementing the BIMfD using current software tools. The results provide the needed technological support for developing tools for BIM-compliant DfD tools in Egypt to encourage deconstruction.

Quantum geometric approach: Nature and characteristics of emerged quantum-conditioned spacetime curvatures on three-sphere

General relativity (GR) in its current classical formulation is fundamentally different from quantum mechanics (QM). We argue that the everlasting battle for exploring and understanding the Universe and then privileging a consistent perception of reality is therefore awaiting a consolidator rather than a conqueror. This should be capable of either unifying these two different benchmarks or at least bringing one closer to another! The latter conservatively describes the consolidating quantum geometric approach, which combines generalization of QM to relativistic energies and gravitational fields and continuous Riemann to discretized Finsler geometry. We found that this type of quantum geometric approach seems to unveil additional quantum-conditioned spacetime curvatures (QCC), sources of gravitation), which obviously could not be disclosed in Einstein’s GR, especially at large scales. This study introduces analytical and numerical analyses of QCC. We conclude that (i) nature and characteristics of QCC are fundamentally distinguishable from the classical GR’s spacetime curvatures, (ii) the QCC are intrinsic, real and essential, i.e. not artifacts that would be removed in a certain coordinate transformation and (iii) the magnitude of QCC are nonnegligible to be underestimated. We also conclude that the spacetime at quantum scales seems to be no longer smooth or continuous so that the proposed quantum geometric approach would be regarded as a novel mathematical framework for the emergence of quantum gravity. Last but not least, a maximal proper force is predicted as a new physical constant, which is responsible for the maximal and gravitational acceleration of a quantum particle that would live in the emerged spacetime curvatures. Thereby, the quantum geometric nature of QCC can be accessed and assessed.

Broadband low-frequency noise attenuation with parallel U-shaped membrane resonators

The attenuation of noise at low frequencies has been the subject of extensive research in the last two decades. Employing membrane-type acoustic metamaterials (MAMs) is one of the most promising solutions due to their lightweight structure and ease of fabrication. This study fabricated a metamaterial with four U-shaped cavities supporting a thin elastic nitrile rubber membrane. We print the U-shaped cavities using fused deposition modeling (3D printing). The sound absorption coefficient (SAC) is calculated using numerical simulations. For SAC computation, an electro-acoustic model is developed that constructs an equivalent electrical circuit based on an impedance analogy. Furthermore, the findings of the numerical and analytical analyses are supported by the actual data acquired from the experiments. We have determined that the average sound transmission loss (STL) is 29.84 dB, and the average SAC exceeds 82% within the frequency range of 500 Hz to 1000 Hz. Due to its lightweight, subwavelength thickness, ability to attenuate broadband noise, and very simple fabrication, this metamaterial is suitable for use in aircraft, automotive industries, and room/building acoustics.

Double-foci acoustic metamaterial Luneburg lens

In this study, an acoustic Luneburg lens is proposed to achieve double foci. High energy density between the two foci can be obtained, which enables the realization of an ultra long acoustic jet between the two foci. The acoustic Luneburg lens is designed based on the gradient index acoustic metamaterial with lattice unit cells. Analytical and numerical analyses were performed to investigate the performance of double foci Luneburg lens. Results show that the double foci can be realized with acoustic jet length goes up to 30 times compared with the wavelength, which has multiple potential applications in medical imaging and energy harvesting.

Analytical and numerical analysis of heat transfer and temperature distribution in laser sintering method

Analytical and numerical analysis of heat transfer and temperature distribution in laser sintering method

Stress Field near Crack Tips in Pressurized Thick-Walled Cylinders with Single and Multiple Cracks in Linear Elastic Fracture Mechanics: Analytical and Numerical Analysis of Stress Field and Crack Behavior

&lt;div&gt;Arrays of radial cracks often appear at the bore of pressurized cylinders, posing potential safety risks and leading to possible structural failures. This article presents an analytical approach to evaluate the stress field arising from single or multiple uniform radial cracks in thick-walled pressurized cylinders within the context of linear elastic fracture mechanics (LEFM) under mode-I loading. This formulation is based on the fundamental equations of elasticity and approximations of stress intensity factors (SIF) reported in the literature. Hence, the SIF were revisited and their range of validity was highlighted. The study considers two types of internal pressure loading: one applied only to the cylinder’s inner surface with no pressure on the crack faces and another applied to both the inner surface and the crack faces. The influence of the number and length of cracks relative to cylinder thickness on the stress field is analyzed. A finite element model of the pressurized vessel is constructed to verify the proposed analytical solution, showing good agreement with numerical results for a limited number of cracks.&lt;/div&gt;