Electronic Processes Research Articles

Charge Transport in the Presence of Correlations and Disorder: Organic Conductors and Manganites.

One of the most fascinating aspects of condensed matter is its ability to conduct electricity, which is particularly pronounced in conventional metals such as copper or silver. Such behavior stems from a strong tendency of valence electrons to delocalize in a periodic potential created by ions in the crystal lattice of a given material. In many advanced materials, however, this basic delocalization process of the valence electrons competes with various processes that tend to localize these very same valence electrons, thus driving the insulating behavior. The two such most important processes are the Mott localization, driven by strong correlation effects among the valence electrons, and the Anderson localization, driven by the interaction of the valence electrons with a strong disorder potential. These two localization processes are almost exclusively considered separately from both an experimental and a theoretical standpoint. Here, we offer an overview of our long-standing research on selected organic conductors and manganites, that clearly show the presence of both these localization processes. We discuss these results within existing theories of Mott-Anderson localization and argue that such behavior could be a common feature of many advanced materials.

Enhancing Electronic Services: Exploring the Optimal Security of Digital Signature Systems

: E-government, e-learning, e-shopping, and e-voting are examples of electronic processes whose efficacy depends on the security, legitimacy, and integrity of the data that is sent back and forth between users. Sensitive material must be extensively vetted by its intended recipient and digitally signed by its original sender in order to meet these benchmarks. Digital signature systems, which are based on intricate cryptographic formulas, are necessary to guarantee the dependability of these electronic services. However, a number of variables, like key and block sizes, computational complexity, security settings, and modifications unique to a given application, affect how well these services function. The goal of the present research was to identify the ideal level of security for electronic mechanisms through a thorough investigation of industry-standard digital signature systems by the authors. They also looked into possible uses in many fields to improve comprehension and application in real-world situations. Key Word: EDMS, Digital Signature, HD5 algorithm, SHA algorithm.

Improving Accuracy of Medication Reconciliation for Hospitalized Children: A Quality Project.

Medication reconciliation is a complex, but necessary, process to prevent patient harm from medication discrepancies. Locally, the steps of medication reconciliation are completed consistently; however, medication errors still occur, which suggest process inaccuracies. We focused on removal of unnecessary medications as a proxy for accuracy. The primary aim was to increase the percentage of patients admitted to the pediatric hospital medicine service with at least 1 medication removed from the home medication list by 10% during the hospital stay by June of 2022. Using the Model for Improvement, a multidisciplinary team was formed at a children's hospital, a survey was completed, and multiple Plan-Do-Study-Act cycles were done focusing on: 1. simplifying electronic health record processes by making it easier to remove medications; 2. continuous resident education about the electronic health record processes to improve efficiency and address knowledge gaps; and 3. auditing charts and real-time feedback. Data were monitored with statistical process control charts. The project exceeded the goal, improving from 35% to 48% of patients having at least 1 medication removed from their home medication list. Improvement has sustained for 12 months. The combination of interventions including simplifying workflow, improving education, and enhancing accountability resulted in more patients with medications removed from their home medication list.

Preface: 5th International Conference on Electronic Science and Automation Control (ESAC 2024)

The 2024 5th International Conference on Electronic Science and Automation Control (ESAC 2024) was held during January 27-28, 2024 in Bangkok, Thailand. The objective of this conference was to provide a common platform to engineers, practitioners, scientists and researchers across the globe for exchanging their knowledge and views to deal with global challenges. The theme of this conference was not only the fundamental technology in the fields of electronic science, information technology, signal processing, communication technology, mechanical automation, and control technology, but also can change our society by exploring new horizons and continuous progress. This scientific event brings together more than 60 national and international researchers. The conference model was divided into three sessions, including keynote sessions, presentations and Q&A discussion. All accepted papers were strictly selected based on originality, significance, relevance, and contribution to the area after being peer-reviewed. We would like to acknowledge all of those who supported ESAC 2024. The help and contribution of each individual and institution was instrumental in the success of the conference. The ESAC Scientific Committee Bangkok, Thailand

Повышение формализации задач верификации топологии и электрической схемы для систем автоматизированного проектирования

The article discusses the study of methods for checking the conformity of the topology and electrical circuit in electronic devices. The authors present a new approach to the analysis and verification of topological structure taking into account electrical characteristics, which leads to increased formalization of problems and provides better optimization of interaction between a person and a computer CAD system. The study includes an analysis of modern methods and tools used in the electronic device design process, and also proposes innovative approaches to ensure consistency between topology and electrical functionality. LVS verification of the project using Caliber, xRC extraction of the project, physical verification of the project using CAD software Cadence Physical Verification System (PVS), LVS verification of the project using PVS are performed. Presents a detailed analysis of the integrated circuit verification process performed using modern CAD tools. The work examines the key stages of verification, including LVS verification of the project using the Caliber tool, xRC extraction of the project, as well as physical verification of the project using the Cadence Physical Verification System (PVS). Particular attention is paid to LVS checks, which are an important design step to ensure compliance with the topology and electrical design. The features of using Caliber to perform LVS checks are discussed, as well as the xRC extraction process to extract parameters of resistors and capacitors. For physical verification of the project, the capabilities of Cadence PVS were used, which provides analysis of compliance of the physical implementation of the circuit with the specified rules. The results obtained and the experience presented in the article can be useful for engineers and researchers involved in the design of integrated circuits, as well as for those interested in the application of modern CAD tools in the field of verification and validation of electronic devices.

Dichotomy of the description of the elastic and electronically inelastic scattering of electrons by methane

The interaction between electrons and methane is studied with a particular focus on describing the dynamics of elastic and electronic excitation processes under the influence of the multichannel coupling effects. Elastic and electronically inelastic integral and differential cross sections are reported. These cross sections were calculated with the Schwinger multichannel method implemented with norm-conserving pseudopotentials within the minimal orbital basis for single-configuration interaction approach with up to 181 open channels. While an excellent agreement with previously published data is found in the elastic channel, the comparisons involving electronic excitation cross sections reveal significant discrepancies. Furthermore, the lack of reliable experimental data regarding the electronically inelastic channels hampers a more detailed analysis of the theoretical results. Additionally, total ionization and total cross sections for electron collisions with methane are also presented. By highlighting the current theoretical challenges in dealing with electron-induced electronic excitation of molecules, we seek to contribute to a deeper understanding of this scattering process and, thus, pave the way for future research.

Dufour and Soret diffusions phenomena for the chemically reactive MHD viscous fluid flow across a stretching sheet with variable properties

The flow of fluid on a slandering stretchable sheet with variable thickness can have several engineering applications like design and optimization of, aerodynamic structures such as wings and airfoils, wind turbine blade design, efficient cooling systems for electronic devices, power plants and industrial processes. Keeping in view these important applications, this work explores Darcy-Forchheimer flow of magnetohydrodynamics (MHD) fluid across a slandering stretchable sheet with variable thickness in the presence of chemically reactive effects, and heat source. The flow is impacted by the combined influences of diffusive-thermo and thermo-diffusive phenomena. The fluid is set into motion along x-axis due to the stretching behavior of the sheet with y-axis as normal to it. Similarity transformations are employed to convert the modeled equations into nonlinear ordinary differential equations. It has observed as outcomes of this study that velocity distribution has augmented with expansion in viscosity factor and has declined with growth in permeability factor, inertia factor, and magnetic factor for both scenarios h1=0.0 and h1=0.5 where the impacts are more significant for the scenario h1=0.0. Thermal distribution has declined with augmentation in Prandtl number, permeability factor and Dufour number while has upsurge with escalation in thermal source factor for both scenarios h2=0.0 and h2=0.5. Concentration distribution has diminished with escalation in Schmidt number, chemical reactivity factor and has augmented with growth in Soret factor for both the scenarios h3=0.0 and h3=0.5 with more significant impacts in the scenario h3=0.0. Stream lines and contour lines for fluid flow have also sketched for the scenarios h1=0.0 and h1=0.5 as well as for M=0.0 and M=2.0. Validation of the proposed model and the methodology has ensured through comparison with fine agreement amongst current results and previously published work.

Far- and mid-infrared FT-IR analysis of the single-crystal pentacene using a linearly polarized synchrotron radiation light source

Understanding and control of molecular vibrations are essential aspects for both fundamental and application considerations of organic semiconductor electronics. The reason is that the organic electronic devices are driven by diverse electronic processes in molecular solids, such as charge carrier transport and excitonic progression, that are strongly influenced by coupling with vibrations. In the present study, molecular vibrations of single-crystals of pentacene, a representative organic semiconductor material, were examined in the far- to mid-infrared range by means of Fourier transform infrared (FT-IR) spectroscopy using a linearly polarized synchrotron radiation light source. The IR absorption spectra exhibited significant modulation depending on the crystalline in-plane azimuthasl angle of c*-oriented single-crystal pentacene.

Dufour and Soret effects on double diffusive Casson fluid flow with the influence of internal heat source

AbstractThis study focuses on the control of the cross-diffusion effects on the thermosolutal Casson fluid stream with an internal heat source. These effects have practical applications in geothermal energy extraction, cooling of electronic devices, petroleum engineering, and polymer processing. With the help of similarity transformations, the governing equations are transformed to nonlinear ordinary differential equations (ODEs). The highly nonlinear differential equations are solved with the help of Bernoulli wavelet numerical scheme, and the outputs are compared with previous literature to validate the findings. The study investigates the forces of various physical parameters on the velocity, temperature, and concentration of the fluid and presents the outcomes in graphical form. In addition, the study provides information on skin friction, heat and mass transfers in tabular format. Overall, the research contributes to a better understanding of the behaviour of non-Newtonian fluids under different thermal and concentration gradients and has practical implications in various industrial processes. Our findings demonstrate the remarkable effectiveness and accessibility of the Bernoulli wavelet method in solving coupled nonlinear ODEs of this nature. The results exhibit outstanding agreement, particularly in engineering applications involving coupled nonlinear ODEs.

Research of the vacuum brake booster working process

The creation of a laboratory installation was carried out with an aim to ensure the study of the working processes and characteristics of vacuum boosters as a part of hydraulic brake drives for vehicles with a gross weight of up to 3.5 tons for civilian usage, and armored vehicles with a gross weight of up to 8.5 tons designated for service and combat missions. Theoretical researches in this direction have been previously carried out by a number of scientists of the Department of “Automobiles” named after prof. Gredeskul A.B. in Kharkiv National Automobile and Road University, the results of which have been highlighted in a number of scientific papers. Comparison of the results of theoretical studies with the experimental ones, received on the laboratory setup and suggested in this paper, according to the experimental method described in the article, using the created electronic signal processing complex and sensor unit, made it possible to establish a discrepancy between theoretical and experimental studies within 6%. This complex for experimental research was created for the first time, thus allowing to obtain the results that confirm the theoretical studies of the vacuum boosters of the brake drive of cars, as well as revealed a number of dependencies between the weight and overall parameters of the under research unit, along with the number of functional relationships between the structural components of the vacuum boosters, which enables to significantly optimize its design.

Electron-phonon coupling dictates electron mean free paths and negative thermal diffusion in metals

The spatiotemporal dynamics of the fundamental energy carriers in metals underpin the efficiency of a wide array of technologies. Although much progress in our understanding of the temporal response of electronic relaxation processes following an external field perturbation has been achieved, the spatial relaxation dynamics of electrons after excitation remains unclear. Here, we employ a scanning ultrafast microscopy with high spatial resolution to directly measure the mean free paths of electrons in different metals. We show that the strength of electron-phonon coupling not only dictates the mean free paths, but also controls a peculiar spatial shrinking of the electronic temperature profile immediately after the electrons have thermalized with the ‘colder’ lattice. More specifically, from our experimental tracking of the spatial relaxation profiles, a clear observation of an effective negative thermal diffusion is apparent for metals with weaker electron-phonon coupling, while for metals with stronger electron-phonon coupling, the negative thermal diffusion effect is not observable. Our spatiotemporal modeling based on the two-temperature approach provides evidence that although negative diffusion occurs universally for materials with two different species that have varying diffusivities and are thermodynamically coupled, effective negative diffusion is masked for cases with stronger coupling between the species.

DFT computation of the electron spectra of thiophene

Recent experiments on thiophene using synchrotron radiation stimulated the present density functional theory (DFT) study of the various types of electron spectroscopy using the DFT methods we developed in our laboratory. Besides the confirmation of the experimental interpretations, the results of the present study strongly validate the methods used for the various types of electron spectroscopy. The average absolute deviations of the DFT results for thiophene from experiment are 0.22 eV for vertical ionization energies of outer valence electrons, 0.10 eV for carbon 1s binding energies, 0.19 eV for vertical valence excitation energies, and 0.18 eV for X-ray absorption energies. The calculated carbon 1s binding energies for bithiophene and terthiophene are also within 0.1 eV of synchrotron experiment. We conclude that workers using synchrotron radiation to study electronic processes of gas-phase molecules can apply our DFT methods for the interpretation of their experimental results.

Enhanced sensitivity of MoS2:Er-based flexible near-infrared photodetectors via tellurium-induced interfacial charge transfer

The persistent photoconductive behavior caused by traps in the active materials usually weakens the sensitivity and stability of photodetectors. Herein, tellurium (Te) microwire and polyvinyl alcohol (PVA) composites were developed as functional flexible substrates to improve the near-infrared (NIR) photoresponse performance of MoS2:Er-based devices with the metal–semiconductor–metal structure. The flexible photodetector exhibits a rise/fall time of ∼2.9–3.1 ms, a responsivity of ∼0.28 mA W−1, and a detectivity of ∼1.41 × 1010 Jones under 808 nm irradiation. The enhanced mechanism can be attributed to the charge transfer between Te microwires and MoS2:Er films, which suppresses the dark current of the device and optimizes the generation process of electron–hole pairs under light illumination. Meanwhile, the flexibility of the device allows it to be employed in human heart rate monitoring. This work offers a simple and essential strategy for constructing integrated flexible NIR photodetectors with high performance.

Application of Machine Learning Methods for Process Optimization in Electronic Packaging Processes

Epoxy resins are commonly used as encapsulation materials in electronic packaging processes. Fluctuations in the materials lead to both changes in processability and to varying quality. Ideally, these variations should be identified, and measures taken as quickly as possible to reduce scrap parts and thus costs. A promising optimization approach for encapsulation processes are machine learning models, which have already shown good results in quality predictions, especially for injection molding. Subsequent quality measurements are avoided with good quality prediction models. With this type of models, not only predictions can be made, but also optimal parameter combinations can be found. In this paper, models for predicting quality criteria warpage and residual enthalpy of the epoxy molding compound were set up, trained and validated. Time series of in-situ sensors were used, from which relevant features were extracted and which, together with machine parameters, provide a dataset for prediction. The most promising prediction models are random forest regression and gradient boosting regression. T hey predict warpage with an accuracy of 90% to 91% and the residual enthalpy with an accuracy of 95%. Subsequently, optimization models of the machine parameters were set up. All relevant target variables were considered in a cost function, through the minimization of which an optimal parameter set was found. The gradient boosted tree and Bayesian optimization were determined to be the most promising models, as they lead to the lowest values of the respective cost function.

Development of a Monte Carlo tool for simulating electron transport in noble liquids

This study presents a Monte Carlo simulation tool for modeling the transportation processes of thermal electrons in noble liquids, specifically focusing on liquid argon and liquid xenon. The study aims to elucidate the microscopical mechanisms governing the drift and diffusion of electrons within the context of time projection chambers (TPCs), with detailed considerations of coherent electron-atom scattering and electric field force. The simulation tool is implemented in the Geant4 framework, allowing for the exploration of electron transport parameters, including drift velocity, longitudinal diffusion coefficient, and transverse diffusion coefficient. The simulation is validated by comparing its results for drift velocity and diffusion coefficients with experimental measurements, revealing reasonable agreement in the low to moderate electric field ranges. Discrepancies between the simulation and experimental measurements are discussed, emphasizing the necessity for enhanced cross-section calculations and high-precision sampling. Despite certain limitations, the simulation tool provides valuable insights into electron transport in noble liquids, establishing a foundation for future enhancements and applications in various research areas

A Multitask Electronic Nose Data Processing Model Based on Transformer Encoder

A Multitask Electronic Nose Data Processing Model Based on Transformer Encoder

Theoretical analysis of the electronic structure and electron collision ionization process in a strongly coupled semi-classical plasma environment

In this work, we propose a distorted wave method in the relativistic framework to analyze the electron collision ionization process under the influence of strongly coupled semi-classical plasmas. A pseudopotential is used to represent the screened interactions between the core and outer electron, together with solving the Dirac equation to take care of the relativistic effects. This potential characterizes the plasma in terms of the Debye screening length and the de Broglie wavelength, which takes into account both the quantum mechanical effects of diffraction (short distance) and the collective effects (long distance). With this method, the traditional central-field potential is modified, the bound- and continuum-electron wavefunctions and the collision matrix elements are estimated under a relativistic Dirac–Coulomb framework. The strongly coupled semi-classical plasma effects on the energies, transition rates, and the electron impact ionization cross sections are investigated in detail, using the hydrogen atom as an example. Our results agree well with other available theoretical data. The reported results and the computational scheme are not only of interest to the communities such as atomic and plasma physics, but also have implications for many other areas, including astrophysical objects, inertial confinement fusion plasmas, etc.

Benchmarking model chemistry composite calculations for vertical ionization potential of molecular systems

In chemical science, the vertical ionization potential (VIP) is a crucial metric for understanding the electronegativity, hardness and softness of chemical material systems as well as the electronic structure and stability of molecules. Ever since the last century, the model chemistry composite methods have witnessed tremendous developments in computing the thermodynamic properties as well as the barrier heights. However, their performance in realm of the vertical electron processes of molecular systems has been rarely explored. In this study, we for the first time benchmarked the model chemistry composite methods (e.g., CBS-QB3, G4 and W1BD) in comparison with the commonly used Koopmans's theorem (KT), electron propagator theory (e.g., OVGF, D2, P3 and P3+) and CCSD(T) methods in calculating the VIP for up to 613 molecular systems with available experimental measurements. The large-scale test calculations strongly showed that the CBS-QB3 model chemistry composite technique can be well recommended to calculate VIP from the perspectives of accuracy, economy and applicability. Notably, the VIP values of up to 7 molecules were identified to have the absolute errors of larger than 0.3 eV at all calculation levels, which have strong hints that their VIP experimental values should be re-investigated.

Vacancy‐Type Defects and Their Trapping/Detrapping of Charge Carriers in Ion‐Implanted GaN Studied by Positron Annihilation

Annealing behaviors of vacancy‐type defects in ion‐implanted GaN are studied by positron annihilation. Mg+ and N+ ions are implanted to obtain 700 nm deep box profiles with Mg and N concentrations of 1 × 1018 cm−3, and the samples are annealed using an ultrahigh‐pressure annealing system. For as‐implanted samples, the major defect species is identified as Ga‐vacancy (VGa)‐type defects. For N‐implanted GaN, the size of the vacancies increases as the annealing temperature increases up to 1100 °C and then shrank above 1200 °C. This behavior is attributed to recombinations between N‐vacancy (VN)‐type defects and excess N. For Mg‐implanted GaN, the major defect species after annealing above 1000 °C is vacancy clusters such as (VGaVN)3. Some of them act as nonradiative recombination centers for blue and ultraviolet luminescence. Their energy levels corresponding to the transition from positive to neutral are located between 2.6 eV above the valence band maximum and the conduction band minimum. The thermal activation process of electron detrapping from the vacancy clusters is also studied. For Mg‐implanted GaN, one of the major secondary defects is collapsed vacancy disks forming dislocation loops. They are eliminated by additional N implantation, which is associated with vacancy agglomerations under the annealing in VGa‐rich condition.

Unveiling the Intrinsic Photophysics in Quasi-Two-Dimensional Perovskites.

The two-dimensional (2D) perovskites have drawn intensive attention due to their unique stability and outstanding optoelectronic properties. However, the debate surrounding the spatial phase distribution and band alignment among different 2D phases in the quasi-2D perovskite has created complexities in understanding the carrier dynamics, hindering material and device development. In this study, we employed highly sensitive transient absorption spectroscopy to investigate the carrier dynamics of (BA)2(MA)n-1PbnI3n+1 quasi-2D Ruddlesden-Popper perovskite thin films, nominally prepared as n = 4. We observed the carrier-density-dependent electron and hole transfer dynamics between the 2D and three-dimensional (3D) phases. Under a low carrier density within the linear response range, we successfully resolved three ultrafast processes of both electron and hole transfers, spanning from hundreds of femtoseconds to several picoseconds, tens to hundreds of picoseconds, and hundreds of picoseconds to several nanoseconds, which can be attributed to lateral-epitaxial, partial-epitaxial, and disordered-interface heterostructures between 2D and 3D phases. By considering the interplay among the phase structure, band alignment, and carrier dynamics, we have proposed material synthesis strategies aimed at enhancing the carrier transport. Our results not only provide deep insights into an accurate intrinsic photophysics of quasi-2D perovskites but also inspire advancements in the practical application of these materials.