Field Analysis Research Articles

Study of the interference fringes–caustic region interaction in a topological Young’s interferometer

Herein, an analysis of the optical field emerging from a topological Young’s interferometer is conducted. The interferometer consists of two 3D-slit shape curves and is studied by projecting it onto a trihedral reference system. From the projection, Airy, Pearcey, and cusped-type beams emerge. The optical field of these beams is organized around its caustic region. The interference between these types of beams presents interesting physical properties, which can be derived from the interaction between the interference fringes and the caustic regions. One property of the interaction is the irradiance flow, which induces a long-distance interaction between the caustic regions. Another property is the bending of the interference fringes toward the caustic regions, which acts as a sink. Due to the adiabatic features of the caustic regions, the interaction between the fringes–caustic and caustic irradiance is studied using a predator–prey model, which leads to a logistic-type differential equation with nonlinear harvesting. The stability analysis of this equation is in good agreement with the theoretical and experimental results.

Identification of psychological stress from speech signal using deep learning algorithm

Psychological activities have various dimensions in which they correlate with their respective behavior generated by the human body. Understanding the relationship of psychological events with the help of external action units is one of the research subjects to explore various human behavior and their dependencies. Existing work applied various deep learning algorithms to outline the correlation between psychological activities with human emotions. The study of psychological analysis in the medical field is very time-consuming and costly. It requires constant monitoring of the patient for a period of time and various interrogation sessions to finalize the emotional severity of an individual. Few skilled specialists and the lack of medical knowledge of human emotions drive the need for computer vision approaches to emphasize emotion recognition, particularly in disorders. The proposed study specifically assesses the use of speech signals to identify psychological disorders in terms of stress characteristics and uses a deep learning model that incorporates feed-forward networks and long short-term memory (LSTM) to identify the degree of psychological disease. The study made use of a standard speech dataset that was gathered from a variety of patients using a standard questionnaire format. The survey was conducted throughout a few Indian states. Speech samples were taken from patients whose cortisol levels were higher than 10 %. To assess the relationship between speech and psychological activity, speech signals from each patient have been gathered. The spectrogram of the speech signal's Mel filter bank coefficients has been analyzed, and the characteristics that cause stress and those that don't have it have been further divided into categories. The suggested model classifies stress and non-stress features in 150 voice dataset subjects with an average accuracy of 98 %. The model is found to be robust for various applications such as preventing suicidal cases, improving decision-making in the diagnosis of depression patients, improves the overall mental healthcare system.

Study on the Natural Smoke Exhaust Performance of Board-Coupled Vertical Shaft in High-Altitude Tunnel Fires

Vertical shaft natural ventilation is a common smoke exhaust method in highway tunnel fires. This study investigated the vertical shaft natural smoke exhaust work in highway tunnel fires with the effect of multiple factors through numerical simulation. Using the analysis of the flow field of smoke in nearby areas of the vertical shaft and the quantitative calculation of the gas exhausted through the vertical shaft, considering the impact of shaft division and board height, an optimal vertical shaft arrangement was proposed, and the working conditions of this arrangement in low-pressure environments were discussed. The results show that dividing a single large vertical shaft into multiple small vertical shafts and appropriately adjusting the board height can reduce the incidence of vertical shaft plug holes and significantly enhance the vertical shaft smoke exhaust performance. Meanwhile, the board-coupled shaft (BCS) has excellent working ability in low-pressure environments, and when pressure drops, smoke exhaust efficiency will improve. This research offers a foundation and reference value for improving the vertical shaft smoke exhaust system in highway tunnels.

Field survey and analysis on near-fault severely damaged high-speed railway bridge in 2022 M6.9 Menyuan earthquake

Field survey and analysis on near-fault severely damaged high-speed railway bridge in 2022 M6.9 Menyuan earthquake

Field Exploration for Colony Selection: Evaluating Hygienic Behavior in Apis cerana indica Colonies

Hygienic behavior (HB) emerges as a pivotal trait, impacting colony resistance to diseases. This study aimed to understand the behavioral traits of Apis cerana indica colonies, with a focus on HB and other key characteristics crucial for colony health, and to screen and identify colonies with superior hygienic behavior and better performance to combat prevailing diseases and pests. This research spans a comprehensive field analysis with different seasons and locations, encompassing the distinct environmental and management factors that influence honey bee behavior. The inclusion of A. cerana indica colonies from various locations provides a novel perspective, offering valuable insights regarding the hygienic behavior of A. cerana indica. Several statistical analyses, including descriptive statistics, principal component analysis (PCA), and Aligned Rank Transformation-Analysis of Variance (ART-ANOVA) for repeated measures, shed light on the distribution of hive metrics, emphasizing the significance of considering seasonality and location-specific factors. PCA highlights unique characteristics in Tirupur and Coimbatore colonies, while correlation analyses uncover relationships among HB, honey, pollen, brood area, and adult population. Moreover, the study’s nuanced findings gave the status of hygienic behavior of A. cerana indica colonies and identified colonies with better colony performance, which will be useful for future breeding programs with A. cerana indica.

Glaucoma Home Self-Testing Using VR Visual Fields and Rebound Tonometry Versus In-Clinic Perimetry and Goldmann Applanation Tonometry: A Pilot Study.

This pilot study aimed to assess the feasibility, accuracy, and repeatability of unsupervised, at-home, multi-day glaucoma testing using the Olleyes VisuALL Virtual Reality Platform (VRP) and the iCare HOME handheld self-tonometer. Participants were trained to use two U.S. Food and Drug Administration-registered or approved devices before conducting self-tests at home over 3 consecutive days. The iCare HOME intraocular pressure (IOP) measurements were collected four times daily per eye, and VRP visual field tests were performed once daily. The results were compared with one in-clinic Humphrey Field Analyzer (HFA) visual field test performed on the day of device training, iCare HOME measurements by the trainer, and the last five Goldmann applanation tonometer (GAT) results. Of 15 enrolled participants, nine of them (60%) completed the study. The six excluded participants could not self-measure using iCare HOME. There was significant correlation between the average mean deviation (MD) values of the at-home VRP tests and in-clinic HFA test (r2 = 0.8793, P < 0.001). Additionally, the average of the sensitivities in five of six Garway-Heath sectors were significantly correlated. VRP test duration was also shorter than in-clinic HFA testing (P < 0.001). Finally, at-home tonometry yielded statistically similar values compared to trainer-obtained iCare HOME values. The mean and range of at-home tonometry were also statistically similar to those for in-clinic GAT, but at-home tonometry demonstrated higher maximum IOP values (P = 0.0429). Unsupervised, at-home, multi-day glaucoma testing using two devices resulted in the capture of higher maximum IOPs than in the clinic and good MD correlation of VRP with HFA. However, 40% of participants could not self-measure IOP using iCare HOME. The study findings suggest that at-home remote glaucoma monitoring correlates with in-office testing and could provide additional information for glaucoma management, although patients had more difficulty with the iCare HOME than the VRP.

Sustainable Maintenance of Conductors in Transmission/Distribution Networks Using Complex Magnetic Field Analysis

This study presents issues related to electromagnetic pollution and the level of magnetic field radiation occurring around conductors used for electricity transmission and distribution. The fact that modeling and simulation are the most efficient methods of optimization, considering the cost–benefit ratio, was the premise of this work. This paper proposes the performance of a complex analysis, carried out in a comparative manner, which includes physical tests and simulations in the existing field around transmission and distribution cables used in transformer substations. In the first stage, the level of the magnetic field existing near the conductor carried by an electric current was tested (measured), and a virtual model was then designed to simulate the field in conditions similar to those of the test. The results obtained from the simulation were analyzed in comparison with those obtained by testing. The maximum permissible limits of exposure to an electromagnetic field, which are regulated by Government Decision HG 520/2016 of 20 July 2016 and Directive 2013/35/EU of the European Parliament and of the Council of 26 June 2013, were used as the reference to formulate conclusions for both situations considered. These comparisons were intended to determine the level of exposure to electromagnetic fields existing in places where electricity transmission/distribution conductors are located. Energy sustainability exists due to the versatile properties of the conductors, with the energy transmission and distribution network being functional regardless of the source of energy production.

Quantitative Analysis of Aeolian Sand Provenance: A Comprehensive Analysis in the Otindag Dune Field, Central Inner Mongolia, China

The identification and quantification of aeolian sand contributions are essential for understanding the formation of dune fields and mechanisms of modern surface processes. In the present study, we take aeolian sand in the Otindag dune field (hereafter, often referred to as, simply, Otindag) as the research object. The dune field’s immediate source is quantitatively identified based on heavy minerals and the Conservativeness Index (CI), Consensus Ranking (CR), and the Consistent Tracer Selection (CTS) method. The primary source area of the aeolian sand was found to be from the northwestern, upwind area of the Otindag (59 ± 14%), followed by the Yinshan Mountain (17 ± 10%) and the lake basin (23 ± 12%). The proposed sediment transport model elucidates that sediments from the upwind of the Otindag are directly transported from the northwest to the Otindag, where they are deposited. Materials from the southern Yinshan Mountains are carried by rivers to the southern edge of the Otindag, where they are subsequently transported by wind and ultimately deposited. The lake deposits within the Otindag also contribute to the aeolian sand supply under the influence of wind. This study demonstrates that the fingerprinting techniques of CI, CR, and CTS serve as successful strategies for conducting quantitative provenance research in dune fields.

Evaluating machine learning techniques for enhanced glaucoma screening through Pupillary Light Reflex analysis

Glaucoma is a leading cause of irreversible visual field degradation, significantly impacting ocular health. Timely identification and diagnosis of this condition are critical to prevent vision loss. A range of diagnostic techniques is employed to achieve this, from traditional methods reliant on expert interpretation to modern, fully computerized diagnostic approaches. The integration of computerized systems designed for the early detection and classification of clinical indicators of glaucoma holds immense potential to enhance the accuracy of disease diagnosis. Pupillary Light Reflex (PLR) analysis emerges as a promising avenue for glaucoma screening, mainly due to its cost-effectiveness compared to exams such as Optical Coherence Tomography (OCT), Humphrey Field Analyzer (HFA), and fundoscopic examinations. The noninvasive nature of PLR testing obviates the need for disposable components and agents for pupil dilation. This facilitates multiple successive administrations of the test and enables the possibility of remote execution. This study aimed to improve the automated diagnosis of glaucoma using PLR data, conducting an extensive comparative analysis incorporating neural networks and machine learning techniques. It also compared the performance of different data processing methods, including filtering techniques, feature extraction, data balancing, feature selection, and their effects on classification. The findings offer insights and guidelines for future methodologies in glaucoma screening utilizing pupillary light response signals.

Internal Buckling Analysis of High Field Pulsed Magnets

Internal Buckling Analysis of High Field Pulsed Magnets

First-principles investigation of lanthanides diffusion in HCP zirconium via vacancy-mediated transport

The diffusion of lanthanide fission products plays an important role in the growth of the fuel-cladding chemical interaction (FCCI) region in metallic fuels. The use of a Zr interdiffusion barrier may mitigate the transport of lanthanides from the fuel to the cladding, but the efficacy of such a liner is not yet known. In this paper, the stability and vacancy-mediated diffusion of La, Ce, Pr, and Nd in hexagonal close-packed (HCP) Zr is investigated via density functional theory (DFT) calculations and self-consistent mean field (SCMF) analysis. DFT is used to calculate the formation, binding, and migration energies of vacancies and vacancy-solute pairs. The DFT energetics are used in the KineCluE code to calculate the Onsager transport coefficients. La is found to be the fastest diffusing species in HCP Zr and experiences an almost isotropic diffusion behavior. The other three species (Ce, Pr, and Nd) demonstrate anisotropic diffusion where the diffusion in the basal planes is significantly faster than that along the c-axis. The calculated lanthanide diffusivities in HCP Zr are fitted to an Arrhenius relation and the activation energies and prefactors are reported for the first time. Furthermore, the vacancy drag and the segregation tendencies were analyzed using the calculated off-diagonal transport coefficients. According to our vacancy-mediated diffusion model, lanthanides are expected to be enriched at vacancy sinks at low temperatures, while at high temperatures, lanthanides are depleted at sinks and will preferably diffuse into the bulk. The enrichment/depletion transition temperature depends on the diffusion direction (basal or axial) and hence will be controlled by the grain texture and orientation.

Study on stable thrust of separated undulating fins

Constrained by their inherent motion characteristics, undulating fins generate fluctuating thrust during movement, which is disadvantageous for precise underwater positioning and control. Drawing inspiration from the principles of biomimicry and leveraging the excellent maneuverability and propulsion capabilities of dragonflies, this study establishes a separated undulating fins model based on the dragonfly's unique front and rear wing structures. The impact of different phases of the separated undulating fins on thrust is studied by numerical simulation methods and quantitatively evaluate thrust stability using the range and standard deviation. Refining relevant theoretical derivations, the mapping relationship between the phase and thrust stability is established. The intrinsic mechanism behind the generation of stable thrust by separated undulating fins is revealed through flow field analysis. A new undulating fin validation platform is designed and constructed, with experimental results demonstrating a good concordance with numerical simulation outcomes. The study reveals that separated undulating fins can effectively reduce thrust fluctuations, with the range of thrust being only 48% of that of traditional undulating fins and the standard deviation being only 35% of that of traditional undulating fins. This research provides a novel approach and theoretical support for the precise control of underwater robots equipped with undulating fins.

Analyzing Research Trends and Future Prospects in Islamic Capital Markets through Bibliometric Mapping

This study conducts a comprehensive bibliometric analysis of the Islamic finance field, utilizing VOSviewer to map out the scholarly landscape and investigate author collaborations, thematic clusterization, and evolving research trends. Our analysis identifies key thematic clusters centered on Islamic banking, Sharia law, and various financial instruments like Sukuk, along with the examination of market dynamics such as volatility and the impact of global disruptions like the COVID-19 pandemic. The study highlights the multidimensional nature of Islamic finance research and pinpoints areas with potential for deeper investigation, particularly in the integration of technology and ethical finance principles into Islamic financial practices. Furthermore, the exploration of author collaboration networks reveals a robust academic community with influential scholars at the core, facilitating a dynamic exchange of ideas and fostering significant research developments. The findings suggest promising directions for future research, emphasizing the need for further integration of interdisciplinary approaches and emerging technologies in the field of Islamic finance. This study serves as a valuable resource for academics, practitioners, and policymakers engaged in Islamic finance, offering insights that can drive future innovations and collaborations in the sector.

Assessment of Different Methods for Estimation of Missing Rainfall Data

AbstractMissing data is a common problem encountered in various fields, including clinical research, environmental sciences and hydrology. In order to obtain reliable results from the analysis, the data inventory must be completed. This paper presents a methodology for addressing the missing data problem by examining the missing data structure and missing data techniques. Simulated datasets were created by considering the number of missing data, missing data pattern and missing data mechanism of real datasets containing missing values, which are often overlooked in hydrology. Considering the missing data pattern, the most commonly used methods for missing data analysis in hydrology and other fields were applied to the created simulated datasets. Simple imputation techniques and expectation maximization (EM) were implemented in SPSS software and machine learning techniques such as k-nearest neighbor (kNN), together with the hot-deck were implemented in the Python programming language. In the performance evaluation based on error metrics, it is concluded that the EM method is the most suitable completion method. Homogeneity analyses were performed in the Mathematica programming language to identify possible changes and inconsistencies in the completed rainfall dataset. Homogeneity analyses revealed that most of the completed rainfall datasets are homogeneous at class 1 level, consistent and reliable and do not show systematic changes in time.

The Minerals That Make Up the Eastern Part of the Balkhab Copper Mine and Its Nearby Rocks

Balkhab copper mine is located in the Balkhab district of Saripul province in the Mir Sayed Murad region at coordinates E 66°46’ and N 35°35’. It is approximately 150 kilometers away from the center of Saripul province and is one of the largest copper mines in the world. The studied area is depicted on the geological map of Balkhab, along with the locations of the collected samples. The purpose of this research is to determine the characteristics of the minerals comprising of the western part of the Balkhab copper mine and its neighboring stones. To write this article, In addition to field and laboratory analyses, a number of other resources mentioned in the references have been used to complete this article. The samples taken from the copper ores were subjected to mineralogical-petrographic and geochemical analysis. This research reveals that the fundamental minerals constituting the copper ore in this area include feldspar, quartz, copper, amphibole, plagioclase, pyroxene, and iron oxide. Additionally, trace amounts of other minerals, such as pyrite, biotite, and OPECs, are present. From the geochemical study, it is seen that in addition to copper, other elements such as Silicon (Si), Sulfur (S), Iron (Fe) and Aluminum (Al) are also included in the composition of copper ore, but their amounts vary. These minerals are predominantly associated with andesitic rocks, including rhyolite, basalt, and dickite. Furthermore, sedimentary rocks like sandstone, pyrite clay, and silicic clay also contain copper minerals. The results obtained from mineralogical-petrographic analysis consistently support the same findings across various studies.

Strategies to promote nuclear energy utilization in hydrogen production

The significant increase in harmful GHG emissions has led to dramatic global climatic changes. Thus, a need arises for clean, sustainable, economically viable energy sources. Prink hydrogen is the production of hydrogen using a nuclear energy source. No clear legislation regulates the utilization and operation of hydrogen in general and pink hydrogen in particular. This study analyzes nuclear energy regulations in various countries and regions and introduces a gap analysis in the nuclear field, comparing the under-established to the well-established regulatory bodies. This study utilized a harmonious blend of analytical tools utilizing both a gap analysis and an integrated decision-making methodology. Gap analysis showed a weak regulatory infrastructure, which hinders the adoption of pink hydrogen in some regions. Strategies were suggested in this study to address the identified weaknesses and threats linked to pink hydrogen technology to enhance energy security.

Research Progress of Biosensor Based on Organic Photoelectrochemical Transistor.

In order to solve the food safety problem better, it is very important to develop a rapid and sensitive technology for detecting food contamination residues. Organic photoelectrochemical transistor (OPECT) biosensor rely on the photovoltage generated by a semiconductor upon excitation by light to regulate the conductivity of the polymer channels and realize biosensor analysis under zero gate bias. This technology integrates the excellent characteristics of photoelectrochemical (PEC) bioanalysis and the high sensitivity and inherent amplification ability of organic electrochemical transistor (OECT). Based on this, OPECT biosensor detection has been proven to be superior to traditional biosensor detection methods. In this review, we summarize the research status of OPECT biosensor in disease markers and food residue analysis, the basic principle, classification, and biosensing mechanism of OPECT biosensor analysis are briefly introduced, and the recent applications of biosensor analysis are discussed according to the signal strategy. We mainly introduced the OPECT biosensor analysis methods applied in different fields, including the detection of disease markers and food hazard residues such as prostate-specific antigen, heart-type fatty acid binding protein, T-2 toxin detection in milk samples, fat mass and objectivity related protein, ciprofloxacin in milk. The OPECT biosensor provides considerable development potential for the construction of safety analysis and detection platforms in many fields, such as agriculture and food, and hopes to provide some reference for the future development of biosensing analysis methods with higher selectivity, faster analysis speed and higher sensitivity.

Enhancing transonic compressor rotor efficiency by flow analysis-driven blade section modification

Abstract Transonic axial compressors are widely used in aero-engines and gas turbines, and their efficiency has a significant influence on the equipment energy utilization rate and fuel cost. In this research, blade section modification based on flow analysis is carried out on the Rotor 67 for improving efficiency. First, the numerical calculation method used is verified with experimental data to ensure the accuracy of the simulation. Then, according to the analysis of simulated flow field and shock structure, the blade section shapes are altered to optimize the blade passage wide distribution for the sections from hub to mid-span. In addition, the blade surface angle is altered to reduce the supersonic flow expansion angle for decreasing shock strength. With these optimizations, the efficiency of modified transonic rotor increases by 0.9 percentage at the design point and 1.0 percentage at near stall point (N = 1.0), respectively. Slightly higher efficiency at off-design speeds (N = 0.9 and 0.8) are also obtained, with maintaining the stall margin.

Computational model-based hemodynamic comparisons of traditional and modified idealized models of autologous radiocephalic fistula.

Autologous arteriovenous fistula (AVF) is a commonly used vascular access (VA) for hemodialysis, and hemodynamic changes are one of the main factors for its failure. To explore the effect of geometry on the hemodynamics in the AVF, a modified model is built with a gradual and smooth turn at the anastomosis and is compared with the traditional model, which has an abrupt sharp turn at the anastomisis. Transient computational fluid dynamics (CFD) simulations were performed for the comparison and analysis of the hemodynamic fields of the two models at different stages of the pulse cycle. The results showed that the low shear stress region and high oscillatory shear stress region in the modified AVF model coincided with regions of intimal hyperplasia that have been identified by previous studies. A comparison with the blood flow velocities measured in vivo was performed, and the error between the simulation results and the medical data was reduced by 22% in the modified model, which verifies the rationality and utility of the modified model.

Magnetic-temperature coupling analysis of a multi-drum dual-coil magnetorheological fluid brake

The coupling analysis of the magnetic field and temperature field of a multi-drum dual-coil magnetorheological (MR) brake is presented in this article. Firstly, the structure of the multi-drum dual-coil MR brake is introduced, and a prototype is manufactured. Thermal analysis of the designed brake is carried out, and a torque correction factor is proposed in order to reduce the error between simulation and experimental results. Then, a coupling analysis model of the magnetic field and temperature is established to study the temperature analysis of the brake under steady-state and transient condition. Simulation results show that the allowable slip power in steady state is 23.68 W. The highest temperature occurs in the fluid gap, and the lowest temperature occurs at the shaft. Under the transient state, the brake can work for about 1200 s under 75.08 W slip power. Furthermore, the temperature characteristics of MR brake under the normal braking, emergency braking, and intermittent braking have been studied. An experimental platform is built to study the torque and temperature characteristics. Results show that the simulated temperature is in good agreement with the experiments, indicating that the proposed magnetic-temperature coupling model can accurately simulate the temperature characteristics of the MR brake.