Analytical Analysis Research Articles

Quadratic Forms in Random Matrices with Applications in Spectrum Sensing

Quadratic forms with random kernel matrices are ubiquitous in applications of multivariate statistics, ranging from signal processing to time series analysis, biomedical systems design, wireless communications performance analysis, and other fields. Their statistical characterization is crucial to both design guideline formulation and efficient computation of performance indices. To this end, random matrix theory can be successfully exploited. In particular, recent advancements in spectral characterization of finite-dimensional random matrices from the so-called polynomial ensembles allow for the analysis of several scenarios of interest in wireless communications and signal processing. In this work, we focus on the characterization of quadratic forms in unit-norm vectors, with unitarily invariant random kernel matrices, and we also provide some approximate but numerically accurate results concerning a non-unitarily invariant kernel matrix. Simulations are run with reference to a peculiar application scenario, the so-called spectrum sensing for wireless communications. Closed-form expressions for the moment generating function of the quadratic forms of interest are provided; this will pave the way to an analytical performance analysis of some spectrum sensing schemes, and will potentially assist in the rate analysis of some multi-antenna systems.

Pure Lovelock gravity regular black holes

We present a new family of regular black holes (RBH) in Pure Lovelock gravity, where the energy density is determined by the gravitational vacuum tension, which varies for each value of n in each Lovelock case. Speculatively, our model may capture quantum effects through gravitational tension. In this way, a hypothetical analogy is drawn between the pair production ratio in the Schwinger effect and our energy density. A notable feature of our model is that the regular solution closely resembles the vacuum solution before reaching the event horizon. For odd n, the transverse geometry is spherical, with phase transitions occurring during evaporation, and the final state of this process is a remnant. For even n, the transverse geometry is non trivial and corresponds to a hyperboloid. In the case of d = 2n+1 with even n, we find an RBH without a dS core and no inner horizon (whose presence has been recently debated in the literature due to the question of whether its presence is unstable or not), and no phase transitions. For d > 2n + 1 with even n, the RBH possesses both an event horizon and a cosmological horizon, also with no inner horizon present. The existence of the cosmological horizon arises without the usual requirement of a positive cosmological constant. From both numerical and analytical analysis, we deduce that as the event horizon expands and the cosmological horizon contracts, thermodynamic equilibrium is achieved in a remnant when the two horizons coincide.

Quantitative fluorescent nanoparticle tracking analysis and nano-flow cytometry enable advanced characterization of single extracellular vesicles.

Current state-of-the-art tools for analysing extracellular vesicles (EVs) offer either highly sensitive but unidimensional bulk measurements of EV components, or high-resolution multiparametric single-particle analyses which lack standardization and appropriate reference materials. This limits the accuracy of the assessment of marker abundance and overall marker distribution amongst individual EVs, and finally, the understanding of true EV heterogeneity. In this study, we aimed to define the standardized operating procedures and reference material for fluorescent characterization of EVs with two commonly used EV analytical platforms-nanoparticle tracking analysis (NTA) and nano-flow cytometry (nFCM). We achieved quantitative fluorescence analyses on ZetaView NTA and NanoAnalyzer nFCM instruments, by utilizing yellow-green FluoSpheres (FS) with assigned ERF (equivalent reference fluorophore) values. This standardization technique allowed for fluorescent EV signal to be expressed in ERF units (indicative of bound fluorescent antibodies per EV), thus enabling measurement of target protein marker abundance on individual EVs, and in the whole EV population. The NTA's and nFCM's limits of detection (LoD) were evaluated at 21 and 9 Alexa Fluor 488 (AF488) molecules, respectively. To complement the limited quantification of markers expressed in a few copies per single EV, in-line bulk fluorescence measurements with a plate reader were performed. This provided absolute marker quantification and more insightful analyses of EV heterogeneity and marker stoichiometry. The standardization method outlined in this work unlocks the full analytical potential of NTA and nFCM, enabling cross-platform data comparison. At the same time, it highlights some of the technical challenges and considerations and thus contributes to the ongoing efforts towards the development of EV analytical tools.

Beyond the youth smile: Investigating techniques and materials in Caroto's paintings by analytical single-point analyses and IR reflectography in full-field

Beyond the youth smile: Investigating techniques and materials in Caroto's paintings by analytical single-point analyses and IR reflectography in full-field

Analytical and Computational Analysis of Damped Frequency of Beams Supported by Elastic Constraints and Visco-Winkler Foundations

Analytical and Computational Analysis of Damped Frequency of Beams Supported by Elastic Constraints and Visco-Winkler Foundations

Importance of pain perception after mucogingival surgery in multiple Miller class III/RT2 gingival recessions: A randomized clinical trial.

Background: Although postoperative pain after mucogingival surgery can modify the patient's daily life, few studies have compared daily postoperative pain in mucogingival surgery considering patient characteristics. The aim of this study was to evaluate postoperative pain in 24 patients with Miller class III/RT2 multiple recessions treated with the modified VISTA (m-VISTA) versus the coronally advanced flap (CAF) with a connective tissue graft (CTG). Material and Methods: Data related to pain intensity (PI), pain duration (PD), analgesic drug intake (AI), and time of analgesic need (TAN) were collected in the “UPV/EHU pain diary”. Other data were also evaluated such as the patient’s central sensitization level, pre-surgical pain, dimensions of CTG, and postoperative incidences were included. A descriptive and analytical statistical analysis was performed. Results: PI (m-VISTA = 11.19 vs. CAF = 8.10) and PD (m-VISTA = 25.27 min. vs. CAF = 10.34 min.) were higher in the test group, being statistically significant at 2 and 8 hours. TAN (m-VISTA = 63.58 min. vs. CAF = 53.25 min.) was higher in the test group, while AI was two times higher in the control group (m-VISTA = 15 vs. CAF = 38). An association was observed between PI and both the length of the SCTG and drugs/alcohol consumption. Conclusions: Postoperative pain was greater in the group of patients treated with m-VISTA. However, these patients showed a higher number of risk factors which might have increased or modified their pain symptoms.

Corrosion Behaviour of Cu-Plate Current Collector under Ex-situ Cyclic Stability Testing for Energy Storage Application

This study compares the corrosion behaviour of a copper plate current collector subjected to an ex-situ cyclic stability test in a 6M KOH and a 6M Na2SO4 electrolyte solution for an electrochemical supercapacitor cell. Through experimental analysis, the change in microstructures resulting from the corrosion behaviour of the copper plate current collector samples are examined by employing various analytical techniques, including microscopy, spectroscopy, and surface roughness analyzer. The corrosion behaviour was studied by employing potentiodynamic polarization and electrochemical impedance spectroscopy analyses. The copper plate current collector samples analysed in 6M KOH and 6M Na2SO4 electrolyte solution showed uniform and localized corrosion product formation, respectively. The CU-72HRS sample recorded a corrosion potential of -608.6mV, -628.87mV, and -89.5mV, -87.588mV using both Tafel and resistance polarization data fitting analysis, respectively, for both 6M KOH and 6M Na2SO4 electrolyte solution using a scan rate of 5mV/s at a voltage window of -1 to 1V. Comparing the microstructural changes under various cyclic conditions provides valuable insights into the durability and reliability of copper plates as current collectors in energy storage systems. The results of this study help improve our understanding of the supercapacitor cell performance in ex-situ cyclic stability tests, assisting in the development of more efficient and durable energy storage technologies.

Cortisol quantification in human plasma and urine by liquid chromatography coupled to mass spectrometry: Validation, analysis and application in a reference population and patients with adrenal incidentalomas.

Cortisol is a glucocorticoid hormone, which is involved in cardiovascular, metabolic, inflammatory and behavioral processes in the human body. Immunoassays, used for routine analysis of analytes, usually lead to erroneous quantification due to the low specificity of these methods. In this study, we developed LC-MS/MS methods with surrogating matrices for evaluating cortisol in both urine and plasma samples and validated them according to Brazilian Health Regulatory Agency guidelines. Urine samples were prepared with an enzymatic hydrolysis stage, followed by a solid-phase extraction (C18 cartridges) using dichloromethane:methanol 9:1 as elution solvent. Plasma samples were prepared by protein precipitation with acetonitrile, using 50μL of sample. HPLC was performed using a C8 column under 300mL min-1 flow gradient conditions with water and methanol, both containing 5mM ammonium formate and 0.1% formic acid. Mass spectrometer with electrospray ionization in positive mode and selected reaction monitoring as detection technique were employed. Calibration curves were linear over a concentration range of 1-200ng mL-1 for urine (r2=0.9950) and 0.5-300ng mL-1 for plasma (r2=0.9970). The methods were selective, showed suitable precision, accuracy, and sensibility (limit of quantification=0.85ng mL-1 for urine and 0.15ng mL-1 for plasma). Validated methods were successful applied to 22 real samples and a cohort of patients [n=63 urines and n=79 plasmas (from the Clementino Fraga Filho University Hospital, Rio de Janeiro, Brazil)].

Scalable fabrication of FeSnO3/gCN (FSO/gCN) nanohybrid: Effective electrocatalyst for oxygen evolution reaction in basic medium

The growing demand for renewable energy has prompted scientists to concentrate on developing robust electrocatalysts for enhanced water-splitting mechanisms. Water-splitting research requires electrocatalysts with superior electrochemical performance and an environmentally favorable character to create significant hydrogen energy resources. In this research, for first time, FSO based on graphitic carbon nitride (gCN) nanohybrid has been produced via an easy hydrothermal route. The developed electrocatalysts were characterized by several analytical analysis to analyze their morphology surface area and crystallinity. Meanwhile, FSO/gCN displayed excellent catalytic characteristics for OER in 1.0 M basic medium (KOH), which demonstrated reduced overpotential (207 mV) to attain 10 mA/cm2 and outstanding durability (20h). It also exhibited a small Tafel plot (37 mV/dec), small onset potential (1.26 V), a higher electrochemical active surface area (ECSA) of 561.5 cm2 and minimal charge transfer resistance (Rct) of 0.04 Ω, significantly superior to FSO material. Significantly, the FSO/gCN nanohybrid demonstrates long-term durability with 73.8 % retention of current density after 20 h. These results suggest that it has the potential to be employed to produce a very efficient and beneficial catalyst for OER, therefore paving the way for future opportunities.

Large deflection angle resonant 1D scanning micromirror fabricated with multi jet fusion 3D printed parts

This paper presents a one-dimensional scanning micromirror, utilizing Multi Jet Fusion three-dimensional (3D) printed polyamide 12 as its core material, with a gold-coated silicon mirror in a half-circle extension shape (4.2 mm × 15 mm). The micromirror serves as a horizontal scanner in a two-dimensional scan module for light detection and ranging. It features a self-supported coil for electromagnetic actuation, and its design is validated through analytical and finite element analyses. The magnetic circuit design is assessed with three magnet configurations. Forced air cooling and salt bath annealing processes are performed to mitigate the effect of Joule heating in the coil and improve the mechanical characteristics of the 3D printed structure. A maximum optical scan angle of 34° was achieved at 1,432 Hz with 90.8 mArms under forced air cooling. The salt bath annealing enhances the long-term reliability significantly, with a 12-hour operational test showing a 1.2% variation in resonant frequency.

Numerical and Analytical Free Vibration Analysis of Composite Plate with Auxetic Core Layer and Functionally Graded Surface Layers

Bu çalışmada, iki fonksiyonel derecelendirilmiş (FD) plaka arasına sandviç edilmiş auxetic çekirdek katmanlı bir sandviç plakanın serbest titreşim analizi, çeşitli sınır koşulları altında hem analitik hem de nümerik yöntemler kullanılarak gerçekleştirilmiştir. FD plakalar, silikon nitrür (

Unified interpretation of the muon g−2 anomaly, the 95 GeV diphoton, and bb¯ excesses in the general next-to-minimal supersymmetric standard model

We investigate three intriguing anomalies within the framework of the general next-to-minimal supersymmetric standard model. These anomalies include a significant deviation of the experimental results for the muon anomalous magnetic moment from its standard model prediction, with a confidence level of 5.1σ; a joint observation by the CMS and ATLAS Collaborations of a diphoton excess with a local significance of 3.1σ in the invariant mass distribution around 95.4 GeV; and a reported excess in the bb¯ production at the Large Electron-Positron Collider with a local significance of 2.3σ. Through analytical and numerical analyses, we provide unified interpretations across an extensive parameter space that remain consistent with current experimental restrictions from data on the Higgs boson at 125 GeV, B-physics measurements, and dark matter observables, as well as existing searches for supersymmetry and extra Higgs bosons. We attribute the muon anomaly to loops involving muon-smuon-neutralino and muon-sneutrino-chargino interactions, while attributing the diphoton and bb¯ excesses to the resonant production of a singlet-dominated scalar. These proposed solutions are poised for experimental tests at the high-luminosity LHC and future linear colliders. Published by the American Physical Society 2024

Influences of Media-Induced Awareness and Sanitation Practices on Cholera Epidemic: A Study of Bifurcation and Optimal Control

Media has a notable impact on reducing disease prevalence, while sanitation measures and heightened awareness can effectively control epidemics by diminishing bacterial growth rates and limiting direct contact with infected individuals. In this study, we propose and analyze an epidemic model to explore how media and sanitation practices influence the dynamics of diseases transmitted through direct contact between susceptible and infected individuals, as well as via bacteria in the environment. Our study entails a combined approach involving both analytical and numerical analyses of the system. We observe that the disease-free and endemic equilibria of the system are interconnected through a forward transcritical bifurcation. We estimate the most important model parameter using authentic cholera data from Sudan for calibration. Our numerical findings suggest that regulating disease transmission through direct contact and environmental bacteria can significantly decrease disease prevalence. Additionally, we note that the growth rate of social media advertisements, along with efforts made by government officials and informed individuals to eliminate bacteria through sanitation coverage, introduces destabilizing effects. However, system stability is reestablished when the baseline number of social media advertisements exceeds a specific threshold. The dissemination of awareness among susceptible individuals, as well as the rate of transfer of informed people to the susceptible class, initially leads to destabilization but eventually stabilizes the system. Disease eradication becomes feasible when the rate of transfer of informed individuals to the susceptible class is very low. Moreover, higher initial values for awareness programs and the dissemination rate of awareness could also eliminate the disease from society. Furthermore, we see that increasing the treatment rate of infectives plays a significant role in achieving disease eradication. Moreover, we investigate an optimal control problem that integrates sanitation interventions and awareness protocols.

Strategy for Enhancing the Performance of Marine and Fisheries Resources Surveillance (Case Study at the Marine and Fisheries Resources Surveillance Base in Tual)

This study aims to formulate strategies to enhance the performance of marine and fisheries resource surveillance at the Marine and Fisheries Resources Surveillance Base (PSDKP) in Tual. The effectiveness of surveillance is a key factor in preserving resources and preventing illegal activities that harm the state. This research employs two main analytical approaches, the Analytic Hierarchy Process (AHP) and SWOT analysis, to identify and prioritize the most relevant strategies. The AHP results indicate that human resources (HR) have the highest weight (0.657), followed by infrastructure and surveillance systems (0.259), and policy (0.084). Based on the SWOT analysis, the prioritized strategies include enhancing HR capacity with a weight of 0.571, developing surveillance systems with a weight of 0.191, strengthening cooperation with a weight of 0.123, and advocating for policy and lobbying with a weight of 0.114. The implementation of these strategies is expected to improve surveillance effectiveness, reduce violations, and support the sustainability of marine and fisheries resources in the PSDKP Tual area.

Modeling the Transmission Dynamics of Avian Influenza in Cattle

Avian Influenza (AI) poses a critical threat to cattle production worldwide, resulting in significant yield losses and economic damages. Despite the severity of AI, comprehensive modeling studies on its transmission dynamics within cattle populations remain limited. In this study, we present a mathematical model to describe the spread of AI among cattle. The model is based on the Susceptible-Infectious-Recovered (SIR) framework, adapted to capture the unique characteristics of AI transmission. The disease-free equilibrium of the model was computed, and the basic reproduction number for AI was calculated using the next-generation matrix method. Sensitivity analysis was conducted using normalized forward sensitivity method to determine the impact of various parameters on the basic reproduction number ($\mathcal{R}_0$). Analytical and numerical analyses indicate that increased contact rates between susceptible cattle and infected virus significantly raise the transmission rate of AI, impacting cattle health and productivity. Sensitivity analysis highlights that the recruitment rates of cattle and infection rates are the most influential parameters affecting $\mathcal{R}_0$. Control measures such as introducing AI-resistant cattle breeds and improving farm management practices to reduce infection rates may be used to mitigate the disease spread. This study enhances the understanding of AI transmission dynamics, providing valuable insights for developing targeted control strategies to protect cattle health and improve production.

A q‐Z Source‐Based Modified Bidirectional Three‐Port Converter for Battery‐Assisted Solar PV Applications

ABSTRACTIn this paper, two separate q‐Z source‐based three‐port converters (TPC) with modified bidirectional networks (BDNs) that offer significant voltage gain for photovoltaic (PV)‐battery applications are proposed. Both designs allow the converter operation to be carried out in four different modes where the power from primary source can flow to the battery as well as the load and the battery alone can also feed power to the load, at lower duty cycle. The designs are based on a q‐Z source converter and use a modified bidirectional path to accommodate the battery port. The main advantage of using one of the two proposed topology is that it provides a common ground for the primary source input (PV), the bidirectional energy storage port, and the output port. In addition to the above mentioned four modes of operation, in the proposed topology, an external switch can be used to charge the battery from the PV source in the absence of the load as well. On the basis of these two distinct advantages, one of the two designs is analyzed in detail. A noncomplex control algorithm is designed to facilitate the battery operation depending upon load power requirement. There are two different duty ratios to control the operation of five MOSFETs to regulate the output voltage. In addition, the converter offers suitable features such as low voltage stress (V) across devices, continuous input current, and common ground (comm.g.) for all three ports, to be used for renewable energy source (RES) applications. The validation of the analytical analysis of the converter is done in a Matlab simulink environment, and the results are presented. For validating the performance of the proposed converter, a 250‐V, 450‐W prototype is implemented and tested at 10 kHz. The converter in stand‐alone mode can attain an efficiency of around 94.5%.

Biocomposite adsorbent (cross-linked chitosan + algae + montmorillonite) for methyl violet 2B dye removal: statistical modelling and optimisation

ABSTRACT Herein, a biocomposite of crosslinked chitosan polyethylene glycol diglycidyl ether (CS-PEDGE), montmorillonite (MMT), and food-grade algae (FGA) was successfully prepared by a hydrothermal technique. The resulting absorbent (CS-PEDGE/FGA/MMT) was assessed for its adsorption property with methyl violet 2B (MV 2B) a toxic cationic dye. The physicochemical properties of CS-EDGE/FGA/MMT were assessed via various analytical techniques, including BET, Elemental analysis, pHpzc, and spectroscopy (FTIR, XRD, SEM-EDX). The influence of three adsorption variables, namely adsorbent dose (A: 0.02–0.1 g/100 mL), solution pH (B: 4–10), and contact time (C: 10–420 min) on the rate of MV 2B dye removal was examined using the Box-Behnken design (RSM-BBD). The findings from the equilibrium isotherm and kinetic analyses suggest that the MV 2B dye adsorption onto the biocomposite surface follow the Freundlich model and pseudo-second-order kinetic models. The biocomposite adsorbent exhibits a maximum dye adsorption capacity (q max ) of 94.2 mg/g. The proposed MV 2B dye adsorption mechanism involves hydrogen bonding, n-π stacking, and electrostatic forces. This research demonstrates the unique structure and outstanding adsorption properties of CS-EDGE/FGA/MMT, which offers a viable solution for removal of detrimental MV 2B dyes from aqueous media.

Comparison of highly sensitive, multiplex immunoassay platforms for streamlined clinical cytokine quantification.

Selecting the optimal platforms to quantitate cytokines is challenging due to varying performance and the plethora of options available. To compare performance of three highly sensitive, multiplex assays on three different platforms - MSD S-plex, Olink Target 48, and Quanterix SP-X - to MSD V-plex which is widely used for quantitative cytokine assay. Serum and stimulated plasma samples were analyzed across each platform. The proportion of quantifiable samples was compared for each analyte and correlation analyses were performed to relate the data. For MSD S-plex, parallelism and antibody pair knockdown experiments gauged specificity of the kit. MSD S-plex was the most sensitive multiplex platform followed by Olink Target 48, Quanterix SP-X, and MSD V-plex. Concentrations across platforms differed greatly for some cytokines, but all platforms showed strong correlation. Results for MSD S-plex were confirmed by parallelism and knockdown. MSD S-plex should be a priority platform for ultra-sensitive assay. Olink Target 48 offers an enticing combination of sensitivity and multiplex capability that warrants consideration when many cytokines require quantitation. MSD V-plex, MSD S-plex and Olink quantitative assays offer high utility across drug development programs, but fit-for-purpose performance should be assessed on a per-analyte basis.

CHANGES IN THE GLOBAL ENERGY SECTOR CAUSED BY RUSSIA'S WAR AGAINST UKRAINE

Problems. The Russian invasion of Ukraine, Russia's refusal to accept the planned volumes of natural gas to the countries of the European Union caused a global energy and financial crisis, and changed the movement towards the development of renewable energy. the transition to sustainable and clean energy sources has become problematic for many countries. Objective. General review and analytical analysis of trends in the development of energy consumption and the introduction of renewable sources in electric power systems in 2017-2023 using the results of research International Energy Agency (IEA), listed in World Energy Outlook (WEO) [1-6]. Methodology of implementation Trends in the development of the world system of renewable power plants to ensure climate neutrality, zero emissions, and a clean ecological environment have been analyzed for the study of the topic article. The study of changes and ways to limit the negative consequences of hostilities in Europe and the Middle East was carried out according to the long-term plans of the IEA. Results. An overview of changes in the structure of energy resources in the world energy balance is presented. It is shown that the energy crisis has led to a sharp increase in the production of fossil fuels, primarily coal and oil. The construction of new capacities for the production of 250 billion tons of liquefied gas has begun. in order to stabilize fuel prices and reduce the price of electricity. Statistical and forecast information on the structure of the world energy balance and annual electricity production by types of generation is provided. The environmental negative consequences registered for the last three years are considered: increased CO2 emissions; air pollution with fine dust; pollution of soils and water horizons; changes in climatic indicators. The problems that have arisen for the implementation of new projects for the construction of renewable sources, the development of electric power infrastructure, security and reliability of power supply are analyzed. An analysis of the proposed measures under several scenarios to increase the production and use of solar, wind and nuclear energy, reduce dependence on traditional energy sources and the prospect of zero carbon dioxide emissions by 2030 is carried out. Conclusions. Actions aimed at reducing energy consumption, projected reduction in fuel prices, planned restarts of nuclear power and further implementation of renewable power plants – these are the proposed measures that make it possible to solve the problems that have arisen around the world. Confidence in meeting the tasks is confirmed by 83 countries and the European Union to meet their commitments to achieve zero carbon dioxide emissions on time and in full. Learning from the experience and directions of development of the world energy sector will create an opportunity for the rapid restoration of the energy structure in Ukraine in the post-war period.

Fostering Edupreneurship Among Students as a Social and Cultural Practice: A Case Study in the German Department at Universitas Negeri Malang

The study aims to promote edupreneurship (educational entrepreneurship) among students through experiential learning and is conducted at the German Department at Universitas Negeri Malang. It endeavors to delineate the infusion of entrepreneurial knowledge and concepts within the learning framework, illustrates the practical application of this knowledge within society by students, and expounds upon the reflective-analysis processes to solidify newly acquired insights. Employing a qualitative descriptive approach, the study collected data through questionnaires, interview sheets, and observation sheets distributed among 12 students enrolled in the Unternehmendeutsch course. The ensuing data analysis involved a continuous analytical cycle encompassing data collection, analysis, and interpretation. The findings underscore that this learning mode significantly expands avenues for acquiring knowledge through firsthand experiences, embracing both errors and successes (trial and error). Consequently, experiential learning emerges as a cognitive process, and the learning experience embodies active thinking and experimentation.