Working Performance Research Articles

A Visualization Experiment on Icing Characteristics of a Saline Water Droplet on the Surface of an Aluminum Plate

When the offshore device, such as an offshore wind turbine, works in winter, ice accretion often occurs on the blade surface, which affects the working performance. To explore the icing characteristics on a microscale, the freezing characteristics of a water droplet with salinity were tested in the present study. A self-developed icing device was used to record the icing process of a water droplet, and a water droplet with a volume of 5 μL was tested under different salinities and temperatures. The effects of salinity and temperature on the profile of the iced water droplet, such as the height and contact diameter, were analyzed. As the temperature was constant, along with the increase in salinity, the height of the iced water droplet first increased and then decreased, and the contact diameter decreased. The maximum height of the iced water droplet was 1.21 mm, and the minimum contact diameter was 3.67 mm. With the increase in salinity, the icing time of the water droplet increased, yet a minor effect occurred under low temperatures such as −18 °C. Based on the experimental results, the profile of the iced water droplet was fitted using the polynomial method, with a coefficient of determination (R2) higher than 0.99. Then the mathematical model of the volume of the iced water droplet was established. The volume of the iced water droplet decreased along with temperature and increased along with salinity. The largest volume was 4.1 mm3. The research findings provide a foundation for exploring the offshore device icing characteristics in depth.

Subcontract under the legislation of Ukraine and the legislation of the EU

The object of this article is social relations that arise in the process of researching civil-law relations in the field of providing services under a contract and a subcontract. And the subject of the study is the comparative characteristics of the contract under the legislation of Ukraine and the legislation of the EU countries.
 In the 60s of the last century, contracts for the provision of services and contracts for the performance of works began to be distinguished in domestic construction and in the construction of foreign countries. The basis for distinguishing between these contracts is that the obligation to perform work and the obligation to provide services mediates economic relations regarding the provision of services, but the services have a dual nature (material and immaterial), which led to the difference in their legal regulation.
 The contract for the provision of services is one of the oldest institutions of private law, the origins of which can be found in Roman law. In classical Roman law, there are detailed contractual structures that mediate the process of providing services. At the same time, it should be noted that there was no detailed definition of their concept in Roman law.
 In Roman law, a contract for the provision of services is understood as a group of contracts under which one party undertakes to provide certain services for the benefit of another party (the lessor), and the lessor – to pay a set fee for these services.
 Probably, initially, the contract for the provision of services was not a special type of contract, and therefore did not have an established contractual structure. Only with the development of trade and civilized thinking, the contract for the provision of services is brought under one of the established structures.
 Consideration of the peculiarities of the legal regulation of subcontracting and subcontracting under the civil legislation of Ukraine and foreign countries is not only interesting, but also relevant. The relevance of this topic lies in the fact that one of the main trends in the development of the modern economy is the rapid growth of the service sector, which covers a wide range of activities aimed at meeting the personal needs of the population and the needs of production, as well as the needs of society as a whole: from trade, transport and financing to insurance, mediation and consulting. The methodological basis consists of the general scientific method of learning legal reality, as well as the following methods: comparative-legal, structural- functional; methods of document analysis, synthesis.
 A subcontract is a civil law contract under which one party (the contractor) undertakes at its own risk to perform certain work on behalf of the other party (the customer), and the customer undertakes to accept and pay for the work performed.

Collaborative optimization on cooling channel flow resistance and winding temperature for integrated cooling of motor and controller

The efficiency and working performance of the motor and controller system in micro-electric vehicles depends mainly on its thermal performance, which is contingent upon effective and active cooling. The working temperature of the motor and controller may be too high during operation, which properly causes motor power reduction or motor breakdowns. Therefore, it is crucial to design a good cooling channel for better cooling the integrated motor and controller system. This work proposes an integrated cooling channel of motor and controller, and the fluid-solid coupling analysis is applied for analyzing the velocity, pressure distributions of the cooling channel, and temperature distributions of motor solid components. Meanwhile, the collaborative optimization method based on the multi-island genetic algorithm (MIGA) is used to attain optimal design parameters of the integrated cooling channel of the motor and controller for obtaining a better cooling channel design with lower flow resistance and lower winding temperatures. Results show that the original cooling channel’s flow resistance and maximum winding temperature are 31.87 kPa and 120.04°C, respectively. The flow resistance and winding temperature are pretty significant. After optimization, the local vortex flow and zero velocity area in optimal cooling channel design are improved, the coolant flow velocity becomes more uniform, and the flow resistance is significantly reduced. The flow resistance and maximum winding temperature of the optimal cooling channel design are 12.5 kPa and 116.76°C, respectively, which are decreased compared with the original cooling channel structure, with a decrease of 39.4% and 2.7%, respectively. The research findings in this work can provide theoretical reference for solid components temperature evaluation of motor and give valuable data to cooling performance evaluation and optimization of integrated cooling channel for motor and controller system.

An adjustable magnetic type resonant multimodal inertial impact motor

The conventional asymmetric inertial impact motors are driven by using the difference in inertial impact forces in the forward and reverse directions, implemented by using asymmetric drive signals, clamping blocks of different sizes or different materials, etc. An adjustable magnetic force type resonant inertia impact motor has been designed, assembled, and tested. The novel motor features a simple and compact structure, allowing for the attainment of different output performance by adjusting the magnetic force to meet various working requirements, and the reverse motion can be easily achieved by simply altering the orientation of the magnet located at the end of the piezoelectric vibrator, without requiring any additional structure The part of the motor’s structure was simulated and optimized using the finite element analysis software COMSOL6.0, with the first and second order vibration modes selected as the working mode. The experimental platform has been established to verify the working performance of the motor. Experimental results demonstrate that, under excitation voltage of 120 VP–P and frequency of 163 Hz, the maximum speed achieved by the motor prototype is 36.55 mm s−1, with maximum load capacity of 320 g, and under excitation voltage of 40 VP–P and frequency of 928 Hz, the minimum step of the prototype reaching up to 134 nm. The motor proposed in this paper features an innovative asymmetric strong magnetic design, enabling high speed and load through the large amplitude of the piezoelectric vibrator in first-order vibration mode. As the amplitude gradually decreases in second and higher order modes, this motor achieves higher displacement resolution, making it has potential applications in high precision positioning and medical fields.

COST ANALYSIS ON THE CONSTRUCTION OF SPORTS FACILITIES IN KEDEWAN SUB-DISTRICT, BOJONEGORO DISTRICT WITH EVM (EARNED VALUE METHOD)

The implementation of construction work has the main targets in construction management, such as construction costs, quality of construction work and construction implementation time. Construction activities can be declared successful in their management if they produce work products with the quality criteria that have been determined, on time, and according to the agreed costs. Using EVM (Earned Value Method) in project management can be used to determine cost performance and implementation time during the project and the indicators used for analysis include: BCWP (Budget Cost of Work Performance), BCWS (Budget Cost of Work Schedule), ACWP (Actual Cost of Work Performance), SV (Schedule Variance), CV (Cost Variance), SPI (Schedule Performance Index), CPI (Cost Performance Index), EAS (Estimated At Schedule) and ETS (Estimated Temporary Schedule). By using this method in the Sports Facilities Construction Project, Kecamatan Kedewan, Kabupaten Bojonegoro, the ACWP (Actual Cost of Work Performed), BCWP (Budgeted Cost of Work Performed), and BCWS (Budgeted Cost of Scheduled) values were obtained. The CV value obtained <0 in weeks 1 to 7 indicates that the costs incurred were greater than the plan, but in weeks 8 to 15 the CV value >0 means that in that week the costs incurred were less than the plan. Meanwhile, meaning the project is experiencing a delay from plan. The estimated of the completion budget requirement obtained from the ETC (Estimate to Compile) value is Rp. 3,345,105,521.28, while the estimated final total project cost obtained from the EAC (Estimate at Complete) value is Rp. 5,680,868,593.22.

Family ideology: uneasy entanglements of eldercare in Germany

AbstractMaterial pressures on privatized households are commonly absorbed through a family ideology, according to which members must pool resources and care for each other, while the family relations they thereby nurture are inherently valuable and constitute their own reward. Drawing on my fieldwork on family‐based eldercare in Germany, I explore the implications of this ideology. Specifically, I argue that it mollifies family caregivers’ unease about the injustices of Germany's eldercare system. Family members are entangled in this system as employers of mostly low‐paid, migrant caregivers; as performers of unremunerated care work at high personal costs; and, if they are women, as reproducers of a gendered division of care labour they object to and resent. Because this entanglement is filtered through the lens of family ideology, the focus of family caregivers shifts away from these broader injustices and towards co‐caregiver conflicts as well as expectations from and commitments towards other family members.

A new MIB-based time integration method for transient heat conduction analysis of discrete and continuous systems

By incorporating the matched interface and boundary (MIB) method into time integration computation, a new MIB-based time integration (MIBTI) approach is proposed for solving transient heat conduction problems in this work. Indeed, this is a truly effective time-domain MIB method that can directly discretize space and time derivatives, and the transient heat conduction problem (an initial-value problem) is transformed into a pseudo-space boundary-value problem. The initial and final time points are regarded as boundary points in the transformed space domain. Two algorithms are developed to deal with the final time point. Unlike conventional recursive schemes for time integration, all unknown variables can be determined by solving the transformed boundary-value problem in the present approach. Various discrete and continuous systems without and with internal heat sources under different boundary conditions are considered to examine the working performance of the proposed method. The applicability of the time stability criterion in the conventional recursive schemes to the proposed method is also discussed. It is found that excellent numerical stability and convergence can be achieved by using the present MIBTI method for solving transient heat conduction problems.

Modification and Performance of a Rotating Biological Contactor for the Rectification of Synthetic Auramine O dye Wastewater

The disposal of domestic and industrial wastewater into the drainage/atmosphere without treatment is a major source of pollution that endangers the health of the population and needs to be controlled. Despite long been used as a secondary treatment strategy for wastewater, conventional rotating biological contactor (RBC) suffers from the drawbacks of limited surface area for the growth of biofilms. There are persistent problems of less oxygenation capacity, and inefficient mixing resulting in inadequate mass transfer. To address these issues conventional RBC has been modified in the present study by replacing a bank of discs using a rotating drum. The use of a rotating drum in RBC enhanced the biofilm attachment surface area up to 2.29 m2 (?108.2% higher than conventional RBC), thereby improving the working performance. To prevent the dissolved oxygen as a limiting factor, four small aerators were placed as supplement aeration system in the wastewater collection tank of modified RBC. To prevent the influence of atmospheric temperature on biological process, a blast-proof aquarium glass heater was placed in the tank. For experimental work, a 700 ppm pretreated synthetic solution of Auramine-O dye as wastewater was utilized. A constant level of percentage variation in biological oxygen demand (BOD) removal efficiency was observed after 15 days of the experiment. After day-15, the MLSS concentration increased to 2960 mg/L, and the BOD concentration reduced to 12.85 mg/L, resulting in a reduction of 89.86% in BOD, indicating the meeting of effluent discharge standards.

Seismic performance analysis of steel frame installed with prefabricated external walls and new connection type

In order to solve the problems existing in prefabricated structure installed with non-structural elements, this paper proposes a new structure type, which is the steel frame installed with prefabricated external wall. Besides, a new connection method is also proposed and designed for this innovative structure type. Based on a specific engineering project, the full-scale pseudo-static cyclic loading test of the steel frame installed with prefabricated external wall (reinforced concrete) is conducted for analyzing the seismic performance of this structural system, which examines the ability of prefabricated external wall to adapt to the deformation of the main structure, the working performance of connection, the damage pattern of the whole structure and the influence of prefabricated wall on the load bearing capacity and stiffness of the main structure. The corresponding numerical simulation by ABAQUS is employed for further investigating the performance of prefabricated external wall and newly proposed connection methods. On the basis of verification about the accuracy of numerical model, the FEA (finite element analysis) models of the detail connection joints with different parameters are established, and the damage distribution, hysteresis curve, skeleton curve and stress distribution are analyzed and compared to explore the influence of the pre-tension force of bolts and thickness of steel plates on the seismic performance of the connections.

The shaking table test and the numerical analysis on a novel viscous damper installation configuration

Most of the existing installation configurations for viscous dampers only consider the structural requirement, ignoring the functional requirement of the architecture. Therefore, an open-space viscous damper installation configuration is proposed and studied by some scholars. Based on the existing research findings, the working performance of the open-space installation configuration for viscous dampers (OSVDIC) in the actual structure remains to be studied. In order to investigate the working mechanism and damping effect of OSVDIC in the structure, the shaking table test is conducted on a three-story steel frame structure model with OSVDIC. Based on the conditions of the shaking table test, the finite-element model of a three-story steel frame structure model with the OSVDIC is established by SAP2000 for time-history analysis. The comparison shows that the numerical analysis results are in good agreement with the shaking table test results. The results of the shaking table test and numerical analysis show that, on the premise of reducing space occupation of the structure, adding the OSVDIC in the structure could significantly lower the seismic response. The effect of the parameters of the OSVDIC on the damping effect of the structure is analyzed by SAP2000. In summary, the structure with OSVDIC could meet the requirements of a certain level of damping effect, while also taking the needs of open space, wide vision, aesthetic appearance, and functional use into account.

Investigation of multifactorial effects on the thermal performance of battery pack inserted with multi-layer phase change materials

The safe and efficient power battery thermal management system (BTMS) is a prerequisite for the effectiveness and long service life of electric vehicles. So, a BTMS with inserted multi-layer phase change materials (PCMs) is proposed to enhance the safety and working performance of battery pack. Effects of PCM settings and operating conditions on the thermal performance of battery pack are discussed and analyzed. The results reveal that PCM cooling plays a significant role in the thermal management of battery pack, where the maximum temperature value and temperature difference of BTMS with multi-layer PCM #C are respectively reduced by 13.61 °C and 2.54 °C compared to battery pack without PCM. Besides, the coupling effects of multiple factors, that is, PCM permutation, the thickness and height of PCMs, and ambient temperature, on the heat dissipation of battery pack are discussed via orthogonal results analysis. The optimized multi-layer PCMs are obtained for the BTMS, i.e., Ps = 121, h1 = 5 mm and L = 6 mm, which achieves the lowest values of Tmax = 43.02 °C and ΔT = 3.37 °C at Tamb = 20 °C. It provides insights for optimizing thermal control strategies for the advancement of thermal management in electric vehicles, ultimately enhancing safety, performance, and longevity.

Structure Optimization of Aerostatic Thrust Bearing Based on Air Film Pressure Field Characteristics Analysis

The air film pressure field (AFPF) of aerostatic thrust bearings significantly determines the working performance of the bearings, and the characteristics of AFPF are closely related to the bearing structure parameters. This study carried out the structure optimization of aerostatic thrust bearing based on the analysis of the AFPF characteristics. The influence law of the number, distribution and the outlet shape of the orifices, as well as the bearing diameter on the static performance of the bearing was investigated. The relationship between bearing structural parameters, AFPF characteristics and bearing static performance was established and effectively used for the structure optimization of aerostatic thrust bearing. The simulation results were verified by the experiment. The results show that the static performance analysis of the aerostatic thrust bearing based on the AFPF characteristics can effectively provide a theoretical basis for the design and optimization of the bearing structure, and improve the bearing performance.

Research on the Creative Performance of Digital Film and Television Works Based on Virtual Reality Technology

Abstract This study investigates the application of virtual reality technology in the creative expression of digital film and television productions, especially the role of EEG signal denoising and feature recognition methods in enhancing the audience experience. The study uses wavelet threshold denoising and parallel RLS adaptive filtering algorithms to process EEG signals to improve the accuracy and reliability of the data. Then, the EEG signals were feature extracted using a bihemispheric domain adversarial neural network (BiDANN) to more accurately recognize the user’s emotional responses. The experimental results show that in the virtual reality environment, the users’ concentration and emotional reactions are significantly improved, with the average concentration reaching 74.21 and the average value of the electrodermal test data being 6.19. In addition, the eye-movement interaction experiments show that different types of digital movie and television works can cause additional attention allocation of users in the VR environment, leading other creative performance effects. The study’s results prove that virtual reality technology can significantly enhance the innovative performance of digital movie and television works and improve the audience’s viewing experience.

Half-decomposition of salt-bearing dolomite.

Half-calcined dolomites (HCDs) have been widely used in environmental remediation, medicine, and construction. However, advanced calcination technologies are required to modify their microstructure and thus improve their working performance. Herein, we investigated the effects of a variety of inorganic salts on the decomposition of dolomite based on thermogravimetric, compositional, and morphological analysis. The thermogravimetric data showed that certain salts significantly lowered the half-decomposition temperature of dolomite, which included LiCl, CaCl2, MgCl2, AlCl3, LiNO3, KNO3, K2CO3, Li2CO3, Li2SO4, Na3PO4, and K3PO4. Compositional analysis demonstrated that only half-decomposition occurred when salt-bearing dolomite was calcined at a temperature of 723-923 K, leading to the formation of CaO-free HCDs composed of periclase and Mg-calcite having a Mg level of 2.0-10.5 mol%. Morphological analysis showed that porous HCDs were feasibly obtained by calcining salt-bearing dolomite at 723-923 K. MgO coarsening occurred at a temperature above 873 K, but it could be avoided by controlling the calcination time. The mechanism of salts may be related to the heterovalent doping effect, which may lead to an increase in the concentration of vacancies in the dolomite lattice.

Design and numerical simulation analysis of a miniature Mixed-flow compressor

This paper completed the pneumatic design of a mixed-flow compressor, adopted RANS turbulence model, and chose Spalart-Allmaras model to complete the numerical simulation of the flow field of the S1 flow surface, meridian flow surface, and impeller surface, and then analyzed the working performance at 90%, 100%, and 110% design speed to explore whether the mixed-flow compressor technology suitable for micro turbojet engines as well as the internal flow field flow state and loss mechanism. The results indicate that the shock wave at the front edge of the main blade and the low energy gas gathered at the tail edge of the main blade and the shunt blade, which causes serious flow blockage, are the main causes of the instability of the mixed-flow compressor at the design point. At 100% design speed, the compressor has higher reliability, stronger adaptability, and the best working performance for its working margin, isentropic efficiency, and pressure ratio with lower loss. The results may provide some references for the further optimization design of the current compressor.

К вопросу о финансировании мероприятий по лесоустройству

It was found that one of the results of the large-scale work carried out by public authorities in 2021 was the reform of the forest inventory system. The performance of forest inventory works remained among the expenditure obligations of the Russian Feder-ation, meanwhile, the changes affected the subjects of realization of this authority, respectively, the financing mechanism has undergone changes. The analysis is presented regarding the efficiency of the organization of forest inventory works in the period preceding the reform, aspects of financing of forest inventory activities in this period, as well as after the entry into force of changes in forest legislation in the field of forest inventory, introduced in 2021; in particular, cases of inaction of authorized pub-lic authorities were identified, as a result of which the work on forest inventory was not carried out properly. A conclusion was made as to the reasons for failure to conduct forest inventory on the lands of the forest fund, among which the key position is taken by insufficient financing. At the same time, cases of financing forest inventory activities from sources not envisaged by the legislation in force in the relevant period of time were revealed. The need for forest inventory is determined based on the need to obtain complete, comprehensive and up-to-date information on the state of forests (both quantitative and qualitative charac-teristics of forests, their territorial location) for rational management in this area. Taking into account the volume of forest inven-tory works to be carried out, as well as financial constraints, it is proposed to introduce a public-private partnership system, which will make it possible to ensure the achievement of objectives in the field of forest inventory, taking into account the limited budgetary funding.

ChatGPT-based Research on the Influence of AI on English Translation

Abstract Since its launch, ChatGPT has generated a great deal of conversation across a range of businesses and sparked an unparalleled technological revolution in the English translation space. In this work, we first establish and thoroughly discuss the English translation standard. We then measure the standard of English translation using HTER, the most widely used human editing distance and assess the quality of ChatGPT’s English translation. The impact of ChatGPT on the quality of English translation is investigated in the context of practice, and the working mechanism, capability characteristics, and performance of ChatGPT are analyzed to reveal the powerful performance of ChatGPT in improving the processing speed and efficiency of translation tasks. When the instances are compared, it can be shown that ChatGPT translations outperform manual translations in terms of linguistic variety. The BF values of word type lexical density and word item lexical indexes are as high as 1503.49 and 1386.72, respectively. Additionally, the BF values of the verb phrase complexity indicator and the ratio of parallel phrases indicate the syntactic complexity of ChatGPT translations, which are both significantly superior to human translations at 38497.02 and 4082.39, respectively.

Numerical Simulation of Plasma Plume With an Insulated Wall in Sheath Region Using a DSMC‐PIC Parallel Algorithm

The spatiotemporal evolution of plasma plumes is accompanied by various phenomena such as chemical reactions, sheath layer formation, and secondary electron emission, which have a crucial impact on the working characteristics and performance improvement of plasma devices. This study uses a direct simulation Monte Carlo/particle‐in‐cell (DSMC/PIC) parallel coupling algorithm for numerical simulations, with the PIC method using full particle simulations. The main focus of the study is to explore, through numerical simulations, the effects of the initial injection density, electron temperature, and charge exchange reactions. Two energy spectrum models are used for secondary electron emission, namely, the Furman model and the vertical model. The modified Mozorov coefficient model simulates two types of insulation wall materials: boron nitride and silicon carbide. The spatiotemporal evolution of H2, H, X, H2+, H+, and e in the flow field is demonstrated by simulating a double cylindrical axisymmetric calculation example. This paper provides a detailed analysis of the structural characteristics of number‐density cloud images under different initial conditions. Increasing the injection density enhances the radial electric field and results in a low‐density region of ion distributions. Furthermore, the electron temperature increases the deposition of wall charges. Lastly, the charge exchange reaction has a weak effect on the specific distribution of particles in the convection field.

Recent advances in tungsten oxide-based chromogenic materials: photochromism, electrochromism, and gasochromism.

As n-type and wide-bandgap semiconductor materials which are widely found in nature, tungsten oxides (WOx) have attracted extensive attention because of their rich phase structures and unique sub-stoichiometric properties. Tungsten oxides have a good chromogenic response to optical, electrical, and gaseous stimuli, in which their phase changes with the change of temperature and ionic embeddedness, accompanied by significant changes in their optical properties. In addition, due to the presence of oxygen defects, the conductivity and adsorption capacity of tungsten oxides for surface substances are enhanced. These properties endow tungsten oxides with promising application potential in the optical and electronic device areas. This paper reviews the structural and optoelectrical properties of tungsten oxide-based chromogenic materials. Then we focus on the working mechanisms, performance indexes, and preparation methods of tungsten oxides in the field of intelligent chromogenic technology, including photochromism, electrochromism, and gasochromism of tungsten oxide-based chromogenic materials. Finally, a conclusion and outlook are provided, which may help to further advance the application of tungsten oxides in the field of smart chromogenic changes.

The relevance and specificity of using choral works by modern composers in the class of «choral conducting»

In the article, the author addresses the issue of the repertoire of choral groups in the class specializing in Choral conducting. Works for a cappella choir have been one of the leading genres in the works of many modern composers for several decades. The popularity of secular choral music is associated with the development of collective musical education in educational institutions, as well as with the active participation of vocal ensembles in concerts, competitions and festivals. Spiritual compositions are also heard no less often, which is explained by the desire of composers and performers for spiritual pursuits that revived at the end of the twentieth century. Modern choral works use various innovative technologies that present a technical difficulty and require a certain methodological approach. The performance of works of this kind has a beneficial effect on improving the level of singing skills and professional competencies of future singers and choral conductors. The educational repertoire of choral students and the list of choral works performed by vocal groups at concerts/competitions/festivals have little overlap. If concert performers increasingly include music by contemporary authors in their program, then classical music still makes up a larger percentage of the repertoire in educational institutions. The following conclusions can be drawn from the study. Works for a cappella choir have been one of the leading genres in the works of many modern composers for several decades. The popularity of secular choral music is associated with the development of collective musical education in educational institutions, as well as with the active participation of vocal ensembles in concerts, competitions and festivals. Religious compositions are also heard no less often, which is explained by the desire of composers and performers for spiritual pursuits that revived at the end of the twentieth century. Updating the repertoire plays an important role in the education of music students. This is not only the study of innovative ideas of modern composers, the use of innovative technologies in teaching, but also the moral and ethical side. We have noted that in the music of the XXI century, the tendency to reflect reality and its constant changes is often applied. The performance of works of this kind has a beneficial effect on improving the level of singing skills and professional competencies of future singers and choral conductors.