Optoelectronic Methods Research Articles

Branched Fluorenylidene Derivatives with Low Ionization Potentials as Hole-Transporting Materials for Perovskite Solar Cells.

A group of small-molecule hole-transporting materials (HTMs) that are based on fluorenylidene fragments were synthesized and tested in perovskite solar cells (PSCs). The investigated compounds were synthesized by a facile two-step synthesis, and their properties were measured using thermoanalytical, optoelectronic, and photovoltaic methods. The champion PSC device that was doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) reached a power conversion efficiency of 22.83%. The longevity of the PSC device with the best performing HTM, V1387, was evaluated in different conditions and compared to that of 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-MeOTAD), showing improved stability. This work provides an alternative HTM strategy for fabricating efficient and stable PSCs.

English

Devices that measure multi-dimensional force torque are suitable for various industrial equipment / machines / processes applications. Such sensors/sensing devices can read the direct physical force and convert it into digital data. In addition to resistive strain gauges, piezoelectric, capacitive, and optoelectronic methods, there are many other ways to measure the strain. Most of these rely on detecting stresses in an elastic structure as their underlying sensing principle. Forcetorque sensors will be necessary because future human assistive equipment/machines will be more interactive with human beings in various unstructured circumstances. Due to criteria and design considerations, not only finding a suitable forcetorque sensor is challenging, but also it incurs high costs. These sensors frequently produce data that include noise and crosstalk problems. A multi-axis force-torque sensor application is discussed in this paper. To decrease noise and crosstalk mistakes, the study presented a control system that simultaneously gives motorized action and uses force as feedback. The proposed system can be evaluated using a variety of metrics; however, the fundamental design challenge is to expand the allowed sensing range while minimizing measurement errors. After thoroughly investigating the necessary data, the requirements for sensors and machine performance are examined. The development of force-torque sensors in the machine and the expansion of their application in the various service machine industries will benefit from this in-depth examination.

Complex Study of a Painted Gypsum XVIII Century Bas-Relief by Optoelectronic Methods to Develop a Combined Cleaning Technique

In this work, a painted gypsum bas-relief from the facades of the inner courtyard of the St. Petersburg Academy of Arts building was examined using UV and visible light photography and optical and electron scanning microscopy, which showed the heterogeneous layers of white painting on the surface of the bas-relief that covered the historical ones. These undesirable layers should be removed during the restoration work, but it was found that the traditional method of removing surface layers of painting with the help of chemical solvents and mechanical cleaning does not solve the problem to the full extent. A cross-section of all the painting layers was prepared to investigate the stratigraphy of the paint layers. These studies were conducted using optical and electron scanning microscopy in order to determine the structure of the paint layers more properly and study the chemical composition of every layer. After this study, a complex cleaning technique was developed. This technique combines chemical and laser cleaning, making it possible to effectively remove the upper dense layers of paint without damaging the historical paint layers.

Analysis of Polarization Images in the Microphysical Blood Parameters Research for the Hematocrit Diagnostics.

The development of non-invasive optoelectronic technologies for human blood monitoring is one of the important research areas for medicine. A critical analysis of optoelectronic methods of blood research and the micromechanical systems based on them is carried out in this article. A design realization of a polarizing portable system for non-invasive monitoring of hematocrit as one of the basic homeostatic constants of the human body containing information about the microphysical parameters of blood cells has been substantiated. A physical model of polarized radiation conversion in a video information system of laser sensing of a biological research object has been formed. Visual and quantitative differences in the spatial distribution of polarization parameters of the scattered radiation for the states of the body with different hematocrit levels have been revealed. A scheme of a multichannel imaging portable system, based on a smartphone using miniature optical and microelectronic components of information conversion for non-invasive monitoring of microphysical blood parameters, has been created. The system implements the principle of polarimetric blood photometry and a multiparametric analysis of the polarization properties of the laser radiation scattered by blood. The developed portable optoelectronic system, based on a smartphone, can be used for rapid blood diagnostics in disaster medicine and the presence of clinical contraindications to the formation of invasive tests. The proposed polarization-based approach is a promising automated alternative to traditional devices and systems for the research of microphysical blood parameters.

Analysis of Transformation Methods of Hydroacoustic and Optoelectronic Data Based on the Tombolo Measurement Campaign in Sopot

Measurements in the coastal zone are carried out using various methods, including Global Navigation Satellite Systems (GNSS), hydroacoustic and optoelectronic methods. Therefore, it is necessary to develop coordinate transformation models that will enable the conversion of data from the land and marine parts to one coordinate system. The article presents selected issues related to the integration of geodetic and hydrographic data. The aim of this publication is to present the various transformation methods and their effects that relate to the data from the tombolo measurement campaign in Sopot conducted in 2018. Data obtained using GNSS Real Time Kinematic (RTK) measurements, Terrestrial Laser Scanning (TLS), the Unmanned Aerial Vehicle (UAV) and the Unmanned Surface Vehicle (USV) were transformed. On the basis of the coordinate transformation methods used, it can be concluded that the adjustment calculus method obtained the best results for the plane coordinates, while the method of P.S. Dąbrowski et al. obtained the best results for the height coordinates. The standard deviation for the difference of the modelled coordinates acquired by the method of P.S. Dąbrowski et al. with respect to the reference coordinates amounted to: 0.022 m (Northing), 0.040 m (Easting) and 0.019 m (height), respectively, while the adjustment calculus method allowed to obtain the following values: 0.009 m (Northing), 0.005 m (Easting) and 0.359 m (height). It can be assumed that a combination of these two seven-parameter transformation methods would provide the best results. In the future, a new seven-parameter transformation method should be developed based on the synthesis of these two existing methods.

Optoelectronic system for controlling an alternating current motor. Electrical and electronic design

A control system for a three-phase induction motor was designed with the use of optoelectronic components and methods. Motor speed was controlled by changing supply voltage frequency. This solution ensures a wide range of rotational speeds, constant torque and effective start-up of an induction motor. The designed motor is supplied with direct current converted to three-phase alternating current. The adopted solution relies on renewable sources of energy to produce DC power. The designed electric motor is controlled by changing supply voltage frequency. Input voltage with the desired waveform is generated by the motor’s electronic system that relies on two microcontrollers. The presented solution features a user interface.

Recent advances on rapid detection and remediation of environmental pollutants utilizing nanomaterials-based (bio)sensors

Environmental safety has become a significant issue for the safety of living species, humans, and the ecosystem as a consequence of the harmful and detrimental consequences of various pollutants such as pesticides, heavy metals, dyes, etc., emitted into the surroundings. To resolve this issue, various efforts, legal acts, scientific and technological perspectives have been embraced, but still remain a global concern. Furthermore, due to non-portability, complex detection, and inappropriate on-site recognition of sophisticated laboratory tools, the real-time analysis of these environmental contaminants has been limited. As a result of innovative nano bioconjugation and nanofabrication techniques, nanotechnology enables enhanced nanomaterials (NMs) based (bio)sensors demonstrating ultra-sensitivity and a short detection time in real-time analysis, as well as superior sensitivity, reliability, and selectivity have been developed. Several researchers have demonstrated the potent detection of pollutants such as Hg2+ ion by the usage of AgNP-MD in electronic and optoelectronic methods with a detection limit of 5–45 μM which is quite significant. Taking into consideration of such tremendous research, herein, the authors have highlighted 21st-century strategies towards NMs based biosensor technology for pollutants detection, including nano biosensors, enzyme-based biosensors, electrochemical-based biosensors, carbon-based biosensors and optical biosensors for on-site identification and detection of target analytes. This article will provide a brief overview of the significance of utilizing NMs-based biosensors for the detection of a diverse array of hazardous pollutants, and a thorough understanding of the detection processes of NMs-based biosensors, as well as the limit of quantification (LOQ) and limit of detection (LOD) values, rendering researchers to focus on the world's need for a sustainable earth.

Lead knee flexion angle is associated with both ball velocity and upper extremity joint moments in collegiate baseball pitchers

ABSTRACT An important aspect of the pitching motion is the lead leg knee angle, from initial lead foot contact to ball release, which can influence pitching performance and injury potential. Understanding the implication of this angle is essential to appropriately coach baseball pitchers. Therefore, the purpose of this study was to determine the lead leg knee flexion influence on both ball velocity and the elbow varus moment. Kinematic and kinetic data were collected using standard optoelectronic motion capture methods from 121 collegiate pitchers and analysed using a random intercept, mixed effects regression model to evaluate the association between the knee angle on peak ball velocity and peak elbow varus moment, independently. Statistically significant associations between the knee flexion angle and ball velocity as well as with the elbow varus moment were noted. The data indicated that a 10° increase in knee flexion at ball was associated with a 2.1 Nm reduction in the peak elbow varus moment (p = 0.021, r2 = 0.12) and a 0.2 m/s reduction in peak ball velocity (p = 0.010, r2 = 0.11). This study provides scientific evidence that the lead knee flexion angle influences both upper extremity stresses and ball velocity.

Analysis of GNSS, Hydroacoustic and Optoelectronic Data Integration Methods Used in Hydrography.

The integration of geospatial data in hydrography, performed using different measurement systems, involves combining several study results to provide a comprehensive analysis. Each of the hydroacoustic and optoelectronic systems is characterised by a different spatial reference system and the method for technical implementation of the measurement. Therefore, the integration of hydrographic data requires that problems in selected fields of electronics, geodesy and physics (acoustics and optics) be solved. The aim of this review is to present selected fusion methods applying the data derived from Global Navigation Satellite System (GNSS), Real Time Kinematic (RTK) measurements, hydrographic surveys, a photogrammetric pass using unmanned vehicles and Terrestrial Laser Scanning (TLS) and compare their accuracy. An additional goal is the evalution of data integration methods according to the International Hydrographic Organization (IHO) S-44 standard. The publication is supplemented by implementation examples of the integration of geospatial data in the Geographic Information System (GIS). The methods described indicate the lack of a uniform methodology for data fusion due to differences in both the spatial reference systems and the techniques used. However, the integration of hydroacoustic and optoelectronic data allows for high accuracy geospatial data to be obtained. This is confirmed by the methods cited, in which the accuracy of integrated geospatial data was in the order of several centimetres.

Improvement of Video Measuring Systems for Electric Traction Network Diagnostics

Purpose. The purpose of the article is system analysis of the state of electric traction networks, as well as methods of complex diagnostics of the contact network from a moving laboratory car to increase the resolution capability of the systems for monitoring the quality of interaction between the contact network and current collectors. Methodology. The problem was solved by theoretical analysis and experimental studies of the current collection parameters, a generalized model of the device for monitoring the wear of the overhead wire and its functional units in order to determine the factors affecting the control error, as well as the development of methods that reduce the specified error. The apparatus of factor analysis, the theory of optoelectronic circuits and methods of statistical information processing were used. Findings. Innovative approaches and qualitatively new diagnostic tools are proposed that allow expanding the functionality of the laboratory cars for testing the contact network for power supply enterprises of electrified railways, industrial and urban electric transport. Hardware and software have been developed to improve the system for measuring the parameters of the overhead wire and other components of the contact network. Originality. The theoretical maximum permissible, from the point of view of the contact network operation, error in monitoring the wear of the overhead wire and other components of the electric traction network has been determined. A method for increasing the resolution capability of a stereo television system and an adaptive lighting system is proposed. It consists in preliminary image transformation and expansion of the dynamic range of image measurement. The ways of introducing a high-speed real-time compression algorithm and using LED backlighting are proposed. Practical value. The quality of the contact network diagnostics in difficult conditions for video surveillance has been improved. A camera with a built-in image compression module without losing its performance is proposed, which allows capturing and transmitting full-frame images to a computing complex for the application of new diagnostic algorithms for contact network components. The modernized video measuring systems for the wear of the overhead wire for monitoring the grounding of the contact network supports are proposed, as well as elements of track facilities located in the visibility zone of specialized cameras, which ensure the operability of the systems at any time of the day at speeds up to 160 km/h. An air curtain subsystem was implemented to protect the cameras.

Optoelectronic methods for detecting air objects and measuring their coordinates

The analysis of optical-electronic methods (OEM) is carried out in order to select and study an OEM capable of solving the problems of detecting and determining the coordinates of small unmanned aerial vehicles. With this aim in view, various OEM measurements of distance to objects are considered. Optoelectronic methods (OEM) in the measurement modes are characterized by high accuracy, which leads to their successful integration with electronic complexes for various purposes. The authors proposed to classify the OEM according to the physical principle into two large groups: active and passive OEM for measuring range. Interference and modulation methods are evaluated. The considered active methods are highly accurate, but require significant energy consumption and do not provide secrecy of work. Passive OEM range measurements are considered in more depth. The OEM with matrix sensors are subdivided into single-chamber and stereoscopic. Methods, that do not require the participation of the human visual apparatus in taking measurement readings and provide complete automation of decision-making, are of particular interest. The considered photosensitive sensors that detect air objects, both day and night, have a matrix structure and can be integrated into a single optoelectronic system for detecting and measuring range. The advantage of the matrix OEM is the ability to use simultaneously all three sensors for day, night and thermal vision, which will allow reliable detection, recognition and measurement of coordinates of small air objects.

Medical and Biological Problems in the Control of Therapeutic Exposure Parameters in Sports Medicine and Ways of Their Solution in New Medical Instruments and Systems

High-quality treatment and recovery of athletes-patients depends on reliable informational diagnosis of injuries and diseases, but also on adequate therapeutic effect. In most cases, the question remains of further predicting the condition of the patient-athlete as a result of the treatment. The article discusses the main biomedical problems in monitoring the therapeutic parameters of exposure and ways to solve them in new devices and systems based on thermometric and optoelectronic methods.

Enabling selective absorption in perovskite solar cells for refractometric sensing of gases

Perovskite solar cells are currently considered a promising technology for solar energy harvesting. Their capability to deliver an electrical signal when illuminated can sense changes in environmental parameters. We have numerically analyzed the variation of the current delivered by a perovskite cell as a function of the index of refraction of air, that is in contact with the front surface of the cell. This calculation identifies which geometrical and material structures enhance this behavior. After replacing the top transparent electrode of a solar cell by an optimized subwavelength metallic grating, we find a large variation in the responsivity of the cell with respect to the change in the index of refraction of the surrounding medium. Such a refractometric sensor can be interrogated electronically, avoiding the cumbersome set-ups of spectral or angular interrogation methods. We present an adaptation of the performance parameters of refractometric sensors (sensitivity and figure of merit) to the case of opto-electronic interrogation methods. The values of sensitivity and Figure of Merit are promising for the development of refractometric perovskite-based sensors.

Ultrafast and Local Optoelectronic Transport in Topological Insulators

Recently, topological insulators (TIs) were discovered as a new class of materials representing a subset of topological quantum matter. While a TI possesses a bulk band gap similar to an ordinary insulator, it exhibits gapless states at the surface featuring a spin‐helical Dirac dispersion. Due to this unique surface band structure, TIs may find use in (opto)spintronic applications. Herein, optoelectronic methods are discussed to characterize, control, and read‐out surface state charge and spin transport of 3D TIs. In particular, time‐ and spatially‐resolved photocurrent microscopy at near‐infrared excitation can give fundamental insights into charge carrier dynamics, local electronic properties, and the interplay between bulk and surface currents. Furthermore, possibilities of applying such ultrafast optoelectronic methods to study Berry curvature‐related transport phenomena in topological semimetals are discussed.

Optical diagnostics of the condition of the cardio vascular system on the basis of optoelectronic methods

In the present work we have investigated the parameters of peripheral blood flow by using a non-invasive method for processing photoplethysmograms (PPGs). The developed original technique allows us to register a photoplethysmogram, isolate the pulse wave and determine the duration of cardio intervals, the duration of the anacrotic and dicrotic phases, the duration of fast and slow blood filling, the expulsion period, the dicrotic and diastolic indices, temporal and amplitude parameters of vascular tone, etc. We observe three types of photoplethysmograms after taking medicaments Corvitol-50 and nitroglycerin. The analysis of the amplitude-temporal characteristics of PPGs allows the determination of key diagnostic parameters.

Using wavelet transforms to suppress light interference in the optoelectronic monitoring system of the weft thread break

The article presents the results of studies on interference suppression in optoelectronic methods for monitoring weft thread weaving looms on the basis of linear image sensors caused by inhomogeneities of the background created by sources of natural or artificial light sources in a controlled image scene. Existing solutions that use linear or nonlinear filtering are focused primarily on the processing of two-dimensional images on personal computers and are unsuitable for use in embedded applications. In particular, their use is also ineffective for solving the above problem, when the useful signal is defined as the difference between the output signals of the photodetector taken at a fixed time interval. As studies have shown, in this case, the best result is the use of discrete wavelet-transform.

A NOVEL NON-INVASIVE CUFF-LESS OPTOELECTRONIC SENSOR TO MEASURE BLOOD PRESSURE

Objective:A newly developed non-invasive cuff-less BP sensor, the TLT Sapphire monitor (Tarilian Laser Technologies, Welwyn Garden City, U.K.) enables high fidelity direct beat-to-beat measurement of BP in digital format using patented optoelectronic methods without need for calibration, compression

Quantitative analysis of degradation mechanisms in 30-year-old PV modules

Quantitative analysis of two 30-year-old PV modules is performed by a combination of the equivalent-circuit model and optoelectronic characterization methods. The two modules under analysis were manufactured in 1984 with the nameplate power of 41.0 W, but degraded under two different conditions; one was operated in the field in Northern California for about 30 years, and the other was stored in a warehouse for the same period. The power outputs of the two modules measured in 2016 are as 28.4W for the field-exposed one and 35.9 W for the warehoused one. We further break down this power difference of 7.5 W ± 0.3 W to specific physical mechanisms. Through the encapsulant transmittance measurements and the circuit modeling of module I–V curves, the power degradation due to encapsulant discoloration is found as 59% ± 4% of the total difference. With the bias-dependent electroluminescence imaging and the dark I–V measurement of solar cells (via the additionally-attached probe wires), the series-resistance increase is attributed to 33% ± 1%, with the split of 13% ± 4% due to interconnection resistance and 20% ± 4% due to cell resistance. In addition, the synergistic effect of all the physical mechanisms makes up the remaining 8% ± 4%. This case study presents an example of analyzing multiple degradation mechanisms of the PV modules. With more characterization data being collected for today's modules, the same analysis framework can be broadly applied, yield great insights module power degradation attributed to multiple loss mechanisms.

ПЕРСПЕКТИВИ, ПЕРЕВАГИ ТА ОСНОВНІ ПРИНЦИПИ ВОЛОКОННО-ЕФІРНИХ ТЕХНОЛОГІЙ ДЛЯ ТЕЛЕКОМУНІКАЦІЙНИХ СИСТЕМ В МІЛІМЕТРОВОМУ ДІАПАЗОНІ ХВИЛЬ

Волоконно-ефірні технології зможуть стати перспективним рішенням для реалізації телекомунікаційних бездротових систем в міліметровому діапазоні хвиль. Фотонні методи формування радіосигналів та волоконно-ефірна архітектура змужуть забезпечити високу пропускну спроможність мереж за рахунок широкої смуги обробки до 10 ГГц, спектрального мультиплексування та використання форматів модуляції високого порядку. У статті проаналізовані перспективи і переваги реалізації бездротових телекомунікаційних систем з використанням волоконно-ефірних технологій в міліметровому діапазоні хвиль. Показані основні принципи фотонних методів формування та модуляції радіосигналів міліметрового діапазону, архітектури гібридної волоконно-ефірної мережі. Проаналізовано складові шуму, дискретність модуляції амплітуди і фази для квадратурного модульованого радіосигналу з використанням фотонних методів понижуючого перетворення частоти.

Multi-Sulfur-Annulated Fused Perylene Diimides for Organic Solar Cells with Low Open-Circuit Voltage Loss

Nonfullerene acceptors are important for increasing the power conversion efficiency of organic bulk heterojunction (BHJ) solar cells. The number of well-performing nonfullerene acceptors is still relatively limited compared to the wide range of donor materials making it difficult to find donor–acceptor pairs with matching optical and electronic properties. We report the synthesis of three sulfur-annulated fused perylene diimide-based compounds (2PDI-2S, 2PDI-3S, and 2PDI-4S) that have varying electron affinity. BHJ solar cells with these acceptors and the donor polymer PTB7-Th have solar power conversion efficiencies above 5% with relatively high fill factors (>60%) for nonfullerene acceptors. The origin of the performance of the BHJs was studied using a combination of physical and optoelectronic characterization methods. X-ray scattering revealed that the domains of 2PDI-nS acceptors are disordered in neat films and in BHJs. The carrier mobility was highest for 2PDI-4S leading to the highest fill factor ...