Optimal Working Conditions Research Articles

Analysis of the working mechanism and detection sensitivity of a flash detector

Abstract Flash detectors are mainly used to detect the brief light flashing when projectiles are launched or exploded in the air. They can output trigger pulse signals in real time to start a test instrument and carry out data collection. Because flash detectors cannot work reliably under strong background light radiation, this work studied the flash detector mechanism. The influence of background light radiance, lens aperture, and detection distance on the effective signal was analyzed, a mathematical model of detection sensitivity based on the background radiation brightness control was proposed, a mathematical formula of the detection distance of the flash detector was deduced, and the optimal working conditions were obtained. The researched model was verified by simulation analysis and actual test experiments, in the same external circumstances, the limit detection distance of the optimal aperture compared to the maximum aperture increased by 20%, and the effective signal voltage amplitude was twice the amplitude at the maximum aperture, and the results showed the correctness of the analysis. The proposed detection sensitivity model can be applied for a dynamic photoelectric detection instrument, which broadens its potential application in the engineering field.

Hybrid quantum thermal machines with dynamical couplings

Quantum thermal machines can perform useful tasks, such as delivering power, cooling, or heating. In this work, we consider hybrid thermal machines, that can execute more than one task simultaneously. We characterize and find optimal working conditions for a three-terminal quantum thermal machine, where the working medium is a quantum harmonic oscillator, coupled to three heat baths, with two of the couplings driven periodically in time. We show that it is possible to operate the thermal machine efficiently, in both pure and hybrid modes, and to switch between different operational modes simply by changing the driving frequency. Moreover, the proposed setup can also be used as a high-performance transistor, in terms of output-to-input signal and differential gain. Owing to its versatility and tunability, our model may be of interest for engineering thermodynamic tasks and for thermal management in quantum technologies.

Efficiency analysis and operating condition optimization of solid oxide electrolysis system coupled with different external heat sources

Coupling external heat sources effectively reduces energy consumption and improves the efficiency of the solid oxide electrolysis (SOEC) system. While an in-depth analysis of the SOEC systems in different coupling scenarios is still needed. According to the internal heat demand and the temperature of external heat sources, three coupling scenarios are defined in this study, i.e., no heat source coupling (Scenario 1), coupled low-temperature heat source (Scenario 2), and coupled high-temperature heat source (Scenario 3). Firstly, the influence of critical parameters on system efficiency is analyzed from two perspectives, including specific system loss and specific energy consumption. The results present that efficiency η1 mainly increases with the rise of steam utilization. Efficiency η2 is not significantly affected by the parameters and is primarily positively correlated with the fuel electrode steam concentration. Efficiency η3 is negatively related to steam utilization, fuel electrode steam concentration, and fuel electrode flow rate, while positively to stack operating temperature. Meanwhile, for Scenarios 1 and 2, the exothermic state of the stack module should be avoided. Furthermore, the system performance maps and stack operating windows in the three scenarios are obtained by changing multiple operating parameters simultaneously and setting constraints. For Scenarios 1 and 2, high system efficiency, high hydrogen production, and long lifetime cannot be achieved simultaneously, so operating parameters need to be selected at a compromise. For scenario 3, high fuel electrode flow rate and low steam utilization can basically meet the above requirements. Both high stack operating temperature and high fuel electrode steam concentration can improve hydrogen production, while the former is mainly beneficial to efficiency η3, and the latter can improve the three efficiencies. The results obtained can be used not only to choose the optimal working conditions of various external heat sources but also to guide the online control and load regulation during system operation.

Rapid quantitative detection of Klebsiella pneumoniae in infants with severe infection disease by point-of-care immunochromatographic technique based on nanofluorescent microspheres.

Background: Klebsiella pneumoniae (KP, K. pneumoniae) is one of the most important nosocomial pathogens that cause severe respiratory infections. As evolutionary high-toxic strains with drug resistance genes increase year by year, the infections caused by it are often accompanied by high mortality, which may be fatal to infants and can cause invasive infections in healthy adults. At present, the traditional clinical methods for detecting K. pneumoniae are cumbersome and time-consuming, and the accuracy and sensitivity are not high. In this study, nanofluorescent microsphere (nFM)-based immunochromatographic test strip (ICTS) quantitative testing platform were developed for point-of-care testing (POCT) method of K. pneumoniae. Methods: 19 clinical samples of infants were collected, the genus-specific gene of mdh was screened from K. pneumoniae. Polymerase chain reaction (PCR) combined with nFM-ICTS based on magnetic purification assay (PCR-ICTS) and strand exchange amplification (SEA) combined with nFM-ICTS based on magnetic purification assay (SEA-ICTS) were developed for the quantitative detection of K. pneumoniae. The sensitivity and specificity of SEA-ICTS and PCR-ICTS were demonstrated by the existing used classical microbiological methods, the real-time fluorescent quantitative PCR (RTFQ-PCR) and PCR assay based on agarose gel electrophoresis (PCR-GE). Results: Under optimum working conditions, the detection limits of PCR-GE, RTFQ-PCR, PCR-ICTS and SEA-ICTS are 7.7 × 10-3, 2.5 × 10-6, 7.7 × 10-6, 2.82 × 10-7ng/μL, respectively. The SEA-ICTS and PCR-ICTS assays can quickly identify K. pneumoniae, and could specifically distinguish K. pneumoniae samples from non-K. pneumoniae samples. Experiments have shown a diagnostic agreement of 100% between immunochromatographic test strip methods and the traditional clinical methods on the detection of clinical samples. During the purification process, the Silicon coated magnetic nanoparticles (Si-MNPs) were used to removed false positive results effectively from the products, which showed of great screening ability. The SEA-ICTS method was developed based on PCR-ICTS, which is a more rapid (20min), low-costed method compared with PCR-ICTS assay for the detection of K. pneumoniae in infants. Only need a cheap thermostatic water bath and takes a short detection time, this new method can potentially serve as an efficient point-of-care testing method for on-site detection of pathogens and disease outbreaks without fluorescent polymerase chain reaction instruments and professional technicians operation.

Degradation study of some pharmaceuticals in commercial formulation by electro‐Fenton process using a dimensionally stable anode cathode: Analytical technique, optimization conditions, and energy consumption

AbstractThe aim of this work was to degrade pharmaceuticals such as amoxicillin (AMX), ceftriaxone (CTX), and Telebrix (TLX) by electro‐Fenton (EF) process using a dimensionally stable anode (DSA) cathode, Pt‐RuO2‐IrO2 (PRI). For this purpose, the optimal conditions of degradation, the pseudo‐first‐order kinetics, the current efficiency, the electrochemical energy consumption (EEC), and the energy cost have been investigated. A spectrophotometric analysis technique has been developed. It is a simple, fast, linear, reliable, and selective technique with LOD = 0.013 g/L and LOQ = 0.04 g/L. The optimum working conditions determined are: Fe2+ = 0.2 mM, pH = 3, j = 20 mA/cm2, and (Pt, PRI) as electrode pair. Under these conditions, the EF process leads to a conversion of the parent compound. In addition, the degradation of compounds by EF follows pseudo‐first‐order kinetics. The EEC for the degradation of 1 kg COD of an organic compound is 99.48, 66.86, and 50.32 kWh kg COD−1 for AMX, CTX, and TLX respectively. The energy cost for processing these compounds is $4.92 (AMX), $10.03 (CTX), and $7.55 (TLX) with current efficiencies between 26% and 51%. Ultimately, the EF process using PRI at the cathode can be used for the treatment of real wastewater from health centres under optimal conditions.

Energy-exergy-economic-environmental (4E) analysis and multi-objective optimization of a cascade LiBr/H2O refrigeration and Organic Rankine cycle integrated system for power generation

This study aims to propose a comprehensive evaluation index which comprises energy, exergy, economy, and environment (4E) for analyzing the novel cascade LiBr/H2O refrigeration and Organic Rankle cycle integrated system for low-grade residual heat recovery. Life cycle assessment (LCA) is used to evaluate the multi-dimensional environmental performances, and a new index, namely Eco-indicator 16 (EI16) is utilized for aggregating multiple environmental impacts in Recipe 2016 method into a quantitative score. Besides, A multi-objective optimization model using net energy generation (NEG), exergy efficiency (ɛ), annual total cost (ATC), and EI16 as the objectives has been developed for sustainability-oriented optimization of the integrated system. NSGA-II is applied for multi-objective optimization, and multiple decision-making methods are used to select the Pareto solution set and obtain the optimal solution. The results show that the payback time is about 5 years under the world average electricity price and interest rate. The optimal working condition increases NEG by 3.27 times, exergy efficiency by 3.26 times, and the ecological index EI16 decreases by 3.23 times at the expense of increasing the ATC by 26.17 %. The system contributes the most to improving the climate and has significant benefits to human health. This study offers guidance for the 4E analysis of a coupled system operating in low-grade residual heat in a cascade.

Effects of Remote Working in Fortune 500 Global Companies

The 500 largest global companies are not just leaders economically, they are also seen as role models. Especially during Covid-19, they had to change their style of work. Most people were not allowed to work in the office anymore. For most people working at home was new to them. But different does not always mean worse. Considering the global companies as examples, they still require a set amount of time for purposes of adaptability. But especially after resolving the issues, people tend to be more productive and can generate greater output than originally expected. Every single company and individual are currently finding their optimal working condition. After the pandemic there will be a time where some colleagues prefer working totally remotely and others not. It will be a time where efficiency will not be measured by hours worked in office, however, rather on the quality of your work and the total output by each individual.

Neutron shielding assessment of a 16O hadron therapy room by means of Monte Carlo simulations with the PHITS code

Hadron radiation therapy is of great interest worldwide. Heavy-ion beams provide ideal therapeutic conditions for deep-seated local tumours. At the Heidelberg Ion Beam Therapy Center (HIT, Germany), protons and carbon ions are already integrated into the clinical routine, while 16O ions are still used for research only. To ensure the protection of the technical staff and members of the public, it is required to estimate the neutron dose distribution for optimal working conditions and at different locations. The Particle and Heavy Ion Transport Code System (PHITS) is used in this work to evaluate the dose rate distribution of secondary neutrons in a treatment room at HIT where 16O ions are used: an equivalent target in soft tissue is considered in the shielding assessment to simulate the interaction of the beam with patients. The angular dependence of neutron fluences and energy spectra around the considered phantom were calculated. Alongside the spatial distribution of the neutron and photon fluence, a map of the effective dose rate was estimated using the ICRP fluence-to-effective dose conversion coefficients, exploiting the PHITS code’s built-in capabilities. The capability of the actual shielding design of the studied HIT treatment room was approved.

Electrochemical Mechanisms and Optimization System of Nitrate Removal from Groundwater by Polymetallic Nanoelectrodes.

Zn-Cu-TiO2 polymetallic nanoelectrodes were developed using Ti electrodes as the substrate. The reaction performance and pollutant removal mechanism of the electrodes were studied for different technological conditions by analyzing the electrochemical properties of the electrodes in the electrochemical system, using Ti, TiO2, Cu-TiO2, and Zn-Cu-TiO2 electrodes as cathodes and Pt as the anode. The Tafel curve was used for measuring the corrosion rate of the electrode. The Tafel curve resistance of the Zn-Cu-TiO2 polymetallic nanoelectrode was the smallest, so the Zn-Cu-TiO2 nanoelectrode was the least prone to corrosion. The electrode reaction parameters were determined using cyclic voltammetry (CV). Zn-Cu-TiO2 polymetallic nanoelectrodes have the lowest peak position and the highest electrochemical activity. The surface area of the electrode was determined by the time-current (CA) method, and it was found that the Zn-Cu-TiO2 polymetallic nanoelectrode had a larger surface area and the highest removal rate of nitrate. The Ti, TiO2, Cu-TiO2, and Zn-Cu-TiO2 electrodes also had higher removal rates for real groundwater, and the differences between the removal rates of nitrates for deionized water and real groundwater decreased as removal time increased. The Zn-Cu-TiO2 polymetallic nanoelectrode exhibited the highest removal rate for real groundwater. This study reveals the reaction mechanism of the cathode reduction of nitrate, which provides the basis for constructing electrochemical reactors and its application in treating nitrate-contaminated groundwater. A mathematical model of optimized working conditions was created by the response surface method, and optimum time, NaCl concentration, and current density were 93.39 min, 0.22 g/L, and 38.34 mA/cm2, respectively. Under these optimal conditions, the nitration removal rate and ammonium nitrogen generation in the process solution were 100% and 0.00 mg/L, respectively.

Kinetic and mechanistic analysis of membrane fouling in microplastics removal from water by dead-end microfiltration

This study explores and analyses the kinetic and mechanistic aspects of microfiltration cellulose acetate membrane fouling by polyamide (PA) and polystyrene (PS) particles in dead-end configuration and the main interactions between the microplastics and the membrane during the filtration process. First, PA and PS particles were characterised to define the differences in shape (regular and irregular), particle size distribution (10–105 µm and 20–320 µm), and surface charge (neutral and negative). The results showed that the prevailing mechanisms during microplastic filtrations were complete pore blocking followed by cake layer formation in both cases. The mechanisms’ kinetics were positively correlated to MPs load through a power-law relationship which was stronger for PS than for PA particles because of higher steric hindrance effects. On the other hand, increasing the working transmembrane pressure led to an optimum working condition, between 0.3 and 0.5 bar for PA and 0.3 bar for PS filtration. Overall, higher fouling was induced by the PA particles due to the higher PA hydrophobicity and their smaller size, which caused a denser cake layer. Instead, PS particles with higher irregularities and repulsive electrostatic forces formed a more porous layer but induced a high degree of abrasion on the membrane surface. Finally, membrane fouling led to an increase in hydrophobicity and roughness, probably causing further fouling. To conclude, modelling membrane fouling can help predict the best working conditions and the membrane replacement cycles to increase the MPs removal efficiency and reduce secondary MP-based pollution.

Machine learning prediction and multiobjective optimization for cooling enhancement of a plate battery using the chaotic water-microencapsulated PCM fluid flows

BackgroundThe cooling of electric vehicle batteries is a crucial issue to increase the performance of the next-generation cars and develop market acceptance. There are various ideas for heat transfer enhancement of the batteries of an electric vehicle. However, it still requires more attention and research to raise the thermal management systems for the batteries. MethodsThe current study seeks the effects of simultaneous use of the chaotic flow and microencapsulate phase change materials for cooling a plate battery. Three values for Reynolds numbers from 100 to 300 and volume fractions from 0 to 10% in various geometries are evaluated. The results are presented through the variations of thermo-hydrodynamic parameters. A multiobjective optimizer combined with an artificial neural network finds optimum working conditions aiding some decision makers. Significant findingsThe Nusselt number of the suspension in the proposed geometries can increase up to 23% compared to that for the pure water in the straight channel. However, it may follow the friction factor strengthening by 160%. It is shown that the proposed geometries are mostly affected by the latter parameter. The efficiency of the proposed geometry accelerates from that of the conventional channel by increasing the Reynolds number and volume fraction.

A Novel Smart Chair System for Posture Classification and Invisible ECG Monitoring.

In recent years, employment in sedentary occupations has continuously risen. Office workers are more prone to prolonged static sitting, spending 65−80% of work hours sitting, increasing risks for multiple health problems, including cardiovascular diseases and musculoskeletal disorders. These adverse health effects lead to decreased productivity, increased absenteeism and health care costs. However, lack of regulation targeting these issues has oftentimes left them unattended. This article proposes a smart chair system, with posture and electrocardiography (ECG) monitoring modules, using an “invisible” sensing approach, to optimize working conditions, without hindering everyday tasks. For posture classification, machine learning models were trained and tested with datasets composed by center of mass coordinates in the seat plane, computed from the weight measured by load cells fixed under the seat. Models were trained and evaluated in the classification of five and seven sitting positions, achieving high accuracy results for all five-class models (>97.4%), and good results for some seven-class models, particularly the best performing k-NN model (87.5%). For ECG monitoring, signals were acquired at the armrests covered with conductive nappa, connected to a single-lead sensor. Following signal filtering and segmentation, several outlier detection methods were applied to remove extremely noisy segments with mislabeled R-peaks, but only DBSCAN showed satisfactory results for the ECG segmentation performance (88.21%) and accuracy (90.50%).

Development of a novel geothermal trigeneration system utilizing modified organic-flash cycle and zeotropic mixtures: Environmental assessment and optimization

Due to the rise in global energy demand caused by growth in the human population and standards of living, renewable energy-based trigeneration systems have gained importance recently. Owing to this, an innovative geothermal-powered trigeneration system is presented to produce electricity, H2, and cooling simultaneously. Also, its performance is scrutinized from the thermodynamic, environmental, and sustainability outlooks to find the best zeotropic mixtures. A two-objective optimization is conducted, taking into account both energetic and exergetic efficiencies as objectives to detect the optimized working conditions. The used mixtures include Butane/Pentane, Butene/Pentane, Isobutene/Pentane, Isobutane/Pentane, R142b/Pentane, R236ea/Pentane, and R245fa/Pentane. Based on studies of the mass fraction of Pentane, the Isobutene/Pentane mixture exhibits the best performance among the zeotropic mixtures. For the Isobutene/Pentane mixture, a rising flash tank temperature leads to reduced net electricity and produced H2 rate, whereas the cooling load goes up. Furthermore, the energetic efficiency of the system has an increasing trend with increments in the temperature of the evaporators in the design. With increasing temperature of the evaporators and flash tank temperature, the CO2 emissions rate has an increasing trend. Finally, there is a considerable amount of exergy destroyed by the vapor generator in both optimal and base operating conditions.

Multi-objective optimization of a concentrated spectrum splitting photovoltaic-thermoelectric hybrid system

This paper presents a comprehensive multi-objective optimization process of the concentrated spectrum splitting photovoltaic-thermoelectric hybrid system, including sensitivity analysis, parameter evaluation, and genetic algorithm. The coupling efficiency and the efficiency difference compared to the concentrated photovoltaic system are simultaneously taken as the optimization objectives. Theoretical models of the two systems are established. The key influencing factors are determined, and their effects on the operating temperatures and efficiencies are investigated. The Pareto front and optimal working conditions are acquired, and the impacts of the thermoelectric figure of merit on the optimization results are further studied. The results demonstrate that the photovoltaic bandgap, splitter cutoff wavelength, concentration ratio, cooling performance, and thermoelectric structure factor are the system's key influencing factors. The two optimization objectives are negatively correlated, attributed to the effect of the PV bandgap. The cost and lifetime need to be further considered to identify the optimal solution. For the current thermoelectric devices, the coupling system achieves the highest coupling efficiency at the photovoltaic bandgap of about 1.42 eV and the maximum system efficiency difference near the photovoltaic bandgap of 1.65 eV.

Environmental impact consideration in the measures to improve the builders of different specialties working conditions

The paper considers working conditions characterized by the presence of harmful and dangerous factors of the natural and industrial environment, as well as the functional body state of builders performing various jobs. As the subject of scientific research, the levels of harmful and dangerous factors of the labor process in the warm and cold periods of the year and physiological indicators characterizing the dynamics of changes in the functional body state of builders working on open construction sites under the influence of the environment were chosen. The purpose of the research is to develop measures to create safe working conditions, as well as to improve the performance and maintain the health of builders. To achieve this goal, the following tasks were solved: the hygienic features of the working conditions of construction work were determined and the leading natural, industrial, harmful and dangerous production factors were identified; the quantitative and qualitative characteristics of harmful factors and the reasons for their formation were studied; professional characteristics of the work of builders with an assessment of the severity and intensity of the labor process were given; a set of measures aimed at optimizing working conditions and maintaining the health of builders was developed. The paper notes that the whole complex of harmful production factors affects the functional state and performance of builders of various professions.

Optimization of chemical oxygen demand removal from petroleum refinery wastewater by electrocoagulation using tubular electrochemical reactor with a novel design

In this study, removal of chemical oxygen demand (COD) from petroleum refinery effluent was investigated using a new tubular electrochemical reactor (TER) design which operated at a batch recycle model. The electrochemical reactor comprises of two concentric electrodes namely spiral aluminum rode anode and hollow cylindrical stainless steel cathode. Four parameters were investigated: current density, sodium chloride concentration (NaCl), pH, and flow rate on the COD removal efficiency, and optimized using response surface methodology. Results show that current density is the most influential parameter on removal percentage where increasing current density results in increasing the removal efficiency. Another effect of lowering flow rate resulted in high removal of COD due to the increased resistance time of effluent passing on the surface of the anode with the newly adopted design. Finding of laboratory work were obtained under optimal working conditions such as current density of 26 mA/cm2, pH of 7.9, NaCl concentration of 1.1 g/L, and flow rate of 2 L/min. These were resulting in a COD removal efficiency of 73.36% with specific energy consumption of 30.61 kWh/kg·COD. Operating cost of the present system was found to be $2.185 m3 which is considered low and acceptable. Experimental results prove that the new design of TER is more efficient than the traditional design that uses in electrocoagulation system to treat wastewater generated from petroleum refinery plants.

Analysis of direct steam generation in parabolic trough solar collectors under hot climate

• We present in the following, all the main contributions of this article. • Modeling and simulation of parabolic trough collectors for direct steam generation. • Numerical investigation of the direct steam generation thermohydraulic behavior. • A parametric analysis using various operating conditions is performed. • The optimal working conditions are proposed for the adopted installation. • Direct steam generation feasibility under climatic condition of Ouarzazate region. Direct steam generation in parabolic trough solar collectors is a promising technology for improving the performance of solar power plants. However, it remains a challenge because it induces liquid-vapor flows in the solar field. This process requires adequate control to avoid the deterioration risk of the receiver tube walls. In the present paper, a detailed numerical model of the system has been presented and validated. The proposed model is based on the conservation laws of the liquid-vapor mixture coupled with the energy balances of the receiver tube and the cover. An accurate parametric analysis is carried out to predict the appropriate operating conditions of the adopted installation. Indeed, the effects of the inlet conditions (mass flow, pressure, and fluid temperature) on the thermohydraulic behavior are investigated. From the obtained results, it emerges that for a good operation of the system, it is suitable to choose a mass flow rate higher than 0.4 kg/s to avoid the stratification phenomenon. Moderate pressure is appropriate to have a compromise between pressure drops and stratification of the mixture flow. The numerical simulation of the system operating under the meteorological conditions of the Ouarzazate region (Morocco) shows that regulation of the inlet flow rate according to the solar flux (0.5-0.75 kg/s for December 17 and 0.5-1.2 kg/s during June 20) and the combination of once-through and recirculation operating mode can ensure a steam production with sufficiently high qualities and durations.

РОЗВИТОК ТА ФУНКЦІОНУВАННЯ РИНКУ МЕДИЧНИХ ПОСЛУГ В УМОВАХ ГЛОБАЛІЗАЦІЇ ТА ІНТЕГРАЦІЇ

The article reveals significant globalization trends of the world market of medical services and unites them into four groups: political (functioning of international organizations, activities of interstate non-governmental organizations and charitable foundations, exit of intellectual property rights protection procedures to the global level), economic (liberalization of trade in medical services , monopolization of the world pharmaceutical market by TNCs, formation of medical clusters), technological (intensification of information exchange, use of international standards of medical care, development of modern treatment methods, medical technologies and equipment) and social (international migration of medical specialists, internationalization of medical education, spread global epidemics). It was determined that these trends have a mostly positive impact on the development of the world market of medical services. One notes that the maximum possible use of the advantages of international cooperation to improve the quality of medical services, the transfer of innovative technologies, the acquisition and development of modern equipment and medicines, the introduction of modern treatment protocols with the simultaneous minimization of the negative consequences of globalization processes must be taken into account when developing strategic plans for transformation and development sphere of health care of Ukraine. The article identifies the negative manifestations of globalization: bureaucratic decision-making process by international organizations, stagnation of national health care systems as a result of the liberalization of trade in medical services, an increase in the general level of drug prices due to a significant level of monopolization of the international pharmaceutical market, a decrease in the number of the working population and shortages qualified workers as a result of labor migration and the internationalization of higher education, the emergence of economic and social crises due to the spread of infectious diseases, the need for significant amounts of investment for the introduction of modern technologies. One identifies the measures to minimize globalization risks: creating optimal conditions for the productive work of medical workers (salary, equipping workplaces, improving qualifications, protecting intellectual property rights, stimulating research and innovation), preventing stagnation in the field of health care by ensuring a constant flow of investment funds (insurance funds of state and non-state institutions, international grants, international cooperation programs, funds of charitable funds), constant improvement of the response system to natural and man-made emergencies.

ОБГРУНТУВАННЯ АКТУАЛЬНОСТІ РОЗРОБКИ СУЧАСНИХ МЕТОДИК ДОСЛІДЖЕННЯ ВИРОБНИЧОГО СЕРЕДОВИЩА З УРАХУВАННЯМ СВІТЛОВОГО ФАКТОРУ

Purpose. Justification of the relevance of development of modern methods of researching the production environment with light factor taking into account. Methodology. Categories of workers in different industries have been considered and related loads on the visual analyzer have been identified. The comparative analysis of the current requirements of the EU and Ukraine for standardizing the light environment at the workplaces of workers performing highly complex visual work has been carried out. Results. The research shows the prevalence of visual works in construction industry and in other industries in Ukraine and in the world. The greatest risk group for the development of occupational diseases as a result of the negative impact of the light environment are workers who perform highly complex visual work. The study of data from world experience, which testify to the importance of the light environment for the formation of optimal working and learning conditions, the prevention of injuries and the occurrence of acquired diseases, leads us to conclusion, that we require the deepen scientific research on the complex influence of all factors of the light environment on the physio-psychological state of workers. That may help us to establish mathematical models of the risk to the health of workers under the conditions of rational use of natural lighting in workplaces and the design of artificial lighting for workers in the category of "engineers and designers" who perform visual work of high complexity, including the use of innovative engineering and technical solutions. Scientific novelty. The category of "engineers and designers" has been defined as a separate group of workers. Our research and analysis of documents regulating the quality of the light environment in premises where visual work of high complexity is carried out, has shown that the current regulatory documents do not fully take into account all the potential dangers of the light environment on workers. This affects the certification of workplaces, the quality of their design and the completeness of the fulfillment of safety requirements regarding the light environment and justifies the relevance of developing new methods of researching the production environment taking into account the light factor. Practical significanse. Improving the methods of researching the production environment taking into account the light factor can allow to increase the safety of work of a wide category of workers in various industries, which is especially important in connection with the spread of automation of production in Ukraine and in the world, and, accordingly, the increase in the category of workers performing work associated with high visual load per person.

Self-Stabilized 50 Gb/s Silicon Photonic Microring Modulator Using a Power-Independent and Calibration-Free Control Loop

This paper demonstrates the possibility of automatically stabilizing the working condition of an integrated Silicon Photonics microring modulator with a novel dithering-based control scheme. The proposed feedback strategy leverages a real-time acquisition of the modulator non-linear transfer function (TF) and operates by setting the target locking point to the zero of the TF second derivative, i.e. where the ring slope is maximum. This results in a control algorithm that is both power-independent and calibration-free. The paper shows that the operating point identified in this way has a negligible difference with respect to the optimum working condition of minimum Transmitter Penalty normally targeted and that the employed dithering signal does not affect the modulation quality. The control performances, made possible by an FPGA-based platform ensuring a 30 ms response time, are assessed in a 50 Gbit/s routing scenario, demonstrating effective compensation of wavelength and thermal variations and successful transmission even in demanding environments.