Flexible Elements Research Articles

Development and Characterization of Hybrid, Temperature Sensing and Heating Yarns with Color Change.

A person's body temperature is an important indicator of their health status. A deviation of that temperature by just 2 °C already has or can lead to serious consequences, such as fever or hypothermia. Hence, the development of a temperature-sensing and heatable yarn is an important step toward enabling and improving the monitoring and regulation of a person's body temperature. This technology offers benefits to several industries, such as health care and sports. This paper focuses on the characterization and development of a hybrid yarn, which can measure and visualize temperature changes through a thermoresistive and thermochromic effect. Moreover, the yarn is able to serve as a flexible heating element by connecting to a power source. The structure of the yarn is designed in three layers. Each layer and component ensures the functionality and flexibility of the yarn and additional compatibility with further processing steps. A flexible stainless steel core was used as the heat-sensitive and heat-conducting material. The layer of polyester wrapped around the stainless steel yarn improves the wearing comfort and serves as substrate material for the thermochromic coating. The resulting hybrid yarn has a reproducible sensory function and changes its resistance by 0.15 Ω between 20 and 60 °C for a length of 30 cm. In addition, the yarn has a uniform and reproducible heating power, so that temperature steps can be achieved at a defined length by selecting certain voltages. The thermochromic color change is clearly visible between 28 and 29 °C. Due to its textile structure, the hybrid sensory and actuating yarn can easily be incorporated into a woven fabric or into a textile by means of joining technology sewing.

Determination of Characteristics and Establishment of Discrete Element Model for Whole Rice Plant

In order to accurately establish a discrete element model for the whole plant flexibility of upright rice during the harvesting period, several physical characteristics, such as geometric features, moisture content, and density, of the entire rice plant were measured, along with frictional properties, such as the static and rolling friction coefficients, and mechanical properties, including the elastic modulus and restitution coefficient. A flexible and upright discrete element model of the rice plant was established using the DEM method based on the Hertz–Mindlin (no slip) and Hertz–Mindlin with bonding mechanical models. The parameters were optimized through Plackett–Burman screening experiments, steepest ascent experiments, and Box–Behnken optimization experiments to accurately determine the discrete element model parameters of each component of the rice plant. The calibration process of the contact parameters between rice grains and steel was analyzed in detail as an example, resulting in a calibration error of 0.68% for the natural repose angle. Taking the calibration of the contact parameters between the main stem and steel as an example, a detailed analysis of the calibration process was conducted. The calibration resulted in a calibration error of 2.76% for the natural repose angle and 2.33% for deflection. This study lays the foundation for understanding the mechanical response of rice and machinery when they are coupled together. Additionally, it provides valuable references for establishing discrete element models of plant species other than rice.

Rapid Prestressed Concrete Retrofit with Prestressed Mechanically-Fastened Fiber-Reinforced Polymer: Field Performance and Observation for a Deteriorated Prestressed Concrete Bridge

This paper presents repairs to rural bridges in North Carolina that deteriorated as a result variously of aging, overweight traffic, and exposure to salts and sulfates. The prestressed concrete C-channel superstructures exhibited prestressing strand loss and displayed significant concrete spalling, with one structure having to be closed to traffic after a routine inspection. Analysis conducted using the American Association of State Highway and Transportations Officials (AASHTO) bridge load rating criteria concluded that repair techniques which strengthen deteriorated flexural elements without also restoring lost prestressing forces are insufficient to maintain load ratings in C-channel structures with heavily damaged prestressing tendons. A prestressed mechanically-fastened fiber-reinforced polymer (MF-FRP) retrofit solution was developed and successfully installed on three structures by the authors and North Carolina Department of Transportation maintenance crews. The most extensive of these three repairs is presented here in detail. The field applications and associated analysis show the temporary MF-FRP repair system is capable of restoring lost prestressing forces, allowing original inventory and operating ratings to remain in place until a permanent superstructure replacement can be scheduled. The most heavily repaired bridge remains in service after 23 months, its performance demonstrated by long-term monitoring data. As currently implemented, the MF-FRP repair is a viable temporary solution for maintaining traffic on a degraded structure while a replacement structure is designed, programmed, and implemented. Efforts to expand the MF-FRP repair into a longer-term solution are underway.

Backbone spiking sequence as a basis for preplay, replay, and default states in human cortex

Sequences of spiking activity have been heavily implicated as potential substrates of memory formation and retrieval across many species. A parallel line of recent evidence also asserts that sequential activity may arise from and be constrained by pre-existing network structure. Here we reconcile these two lines of research in the human brain by measuring single unit spiking sequences in the temporal lobe cortex as participants perform an episodic memory task. We find the presence of an average backbone spiking sequence identified during pre-task rest that is stable over time and different cognitive states. We further demonstrate that these backbone sequences are composed of both rigid and flexible sequence elements, and that flexible elements within these sequences serve to promote memory specificity when forming and retrieving new memories. These results support the hypothesis that pre-existing network dynamics serve as a scaffold for ongoing neural activity in the human cortex.

Simple Mathematical Models for the Dynamics Of Spacecraft With Deployed Solar Panels

Most present day spacecrafts have large interconnected deployed solar panels having very low natural frequencies. The control torque applied to maneuver the spacecraft sets up transient oscillations in the spacecraft. The present work studies the nature of these interactions. The spacecraft in orbit can be modeled as a free rigid mass with flexible elements attached to it. It is shown that the oscillations of the spacecraft body are characterized by the dynamic characteristics of the flexible panel even if the mass and mass moment of inertia of the body is signifcantly higher than that of the flexible panels. A simple model consisting of an Euler-Bernoulli beam attached to a mass can represents such a system. The infuence of various parameters of the Euler-Bernoulli beam and the rigid element on the disturbances caused in the rigid element are investigated. The characteristics are determined for a step and also for a torque input. The responses are obtained in terms of nondimensionalised quantities. It is demonstrated that using the simple model developed the responses of spacecraft body can be easily obtained.

Swift Assessment of Flexible Elements of High Speed Flexible Couplings for Aircraft Transmission Systems

The High Speed Flexible Coupling (HSFC) known as Power Take-Off shaft (PTO) is used in combat aircraft for connecting engine gearbox with accessory gearbox to transmit power and to accommodate larger misalignments. The HSFC utilizes series of metallic contoured plates as flexible elements. The development of a HSFC shaft assembly involves high cost and time process. Any failure of the HSFC during flight operation will deprive the secondary power system mainly used for controlling the single engine fighter aircraft. To develop the reliable HSFC with minimum developmental cost and time, an innovative approach termed as Swift Assessment of Flexible Elements (SAFE) for the development of HSFC is evolved. A case study of a typical high speed flexible coupling developed using this approach is presented With the SAFE approach, sufficient level of flexibility in design modification, trim down product development cycle time and cost were realized.

Analysis of tapered three-layered sandwich flexural members (Stobie poles) with partial shear interaction: Analytical model

This research paper presents an analytical model for predicting the load–deflection curves of three-layered sandwich (TLS) beams with interlayer slips, accounting for material nonlinearity in all three layers. An advanced 1D beam element with five degrees of freedom per node was developed to simulate the structural behaviour of TLS beams, with two additional degrees of freedom for slippage between adjacent layers. The Euler–Bernoulli kinematic assumptions were adopted, and the governing equations were derived based on equilibrium equations, followed by the derivation of the weak form equations. The finite element formulation was then developed, and the Newton–Raphson scheme was adopted for the solution of the nonlinear system of equations, with five-point Gaussian quadrature used for the integration over the length of the beam and trapezoidal integration used for the integration over the area of the cross section. The proposed model was applied to tapered steel-concrete-steel sandwich flexural elements known as Stobie poles. The model results were verified with full-scale experimental tests and numerical models, and the effects of slippage constitutive relationship, cross-section tapering, and mechanical properties of the core and skin layers were evaluated. The presented model provides a reliable tool for designing and analysing three-layered sandwich beams with partial shear interaction.

The state of art of μ-RWELL technology

The μ-RWELL is a single-amplification stage resistive Micro-Pattern Gaseous Detector (MPGD). The detector amplification element is realized with a single copper-clad polyimide foil micro-patterned with a blind hole (well) matrix and embedded in the readout PCB through a thin Diamond-Like-Carbon (DLC) sputtered resistive film. The introduction of the resistive layer, suppressing the transition from streamer to spark, allows to achieve large gains (≥ 104) with a single amplification stage, while partially reducing the capability to stand high particle fluxes. The simplest resistive layout, designed for low-rate applications, is based on a single-resistive layer with edge grounding. At high particle fluxes this layout suffers of a non-uniform response. In order to get rid of such a limitation different current evacuation geometries have been designed. In this work we report the study of the performance of several high rate resistive layouts tested at the CERN H8-SpS and PSI πM1 beam test facilities and with a high intensity 5.9 keV X-ray tube. These layouts fulfill the requirements for the detectors upgrades at the HL-LHC and for the experiments at the next generation colliders FCC-ee/hh and CepC.The possibility to realise the detector on flexible elements opens the way to use the technology for non-planar geometry such as the instrumentation of the Inner Tracker at future Charm-Tau factories. In addition, it must be stressed that the μ-RWELL device can be manufactured with full sequential-build-up technology, thus allowing a straightforward technology transfer of the manufacturing process to the industry.

Generalized Nested Array Configuration Family for Direction-of-Arrival Estimation

Sparse arrays have obvious superiority in array element layout and the number of degrees of freedom (DOF) for resolving more sources than the number of physical sensors with high estimation accuracy. Nevertheless, any of the existing array configurations with fixed number of sensors corresponds to a certain array element arrangement, the virtual coarray and the uniform DOF may be affected significantly when the positions of one or several sensors changed. In this paper, a generalized nested array (GNA) configuration family is proposed by incorporating the concept of family into array design. The arrays in GNA family generally consist of three subarrays, and the inherent geometric characteristic is analyzed from the perspective of two-dimensional (2D) representation. For the array configurations of GNA family, one can be transformed into another by setting order factor, thus they can provide more flexible element arrangements as compared to a specific array configuration. Moreover, each array of the GNA family has hole-free difference coarray. Based on the GNA family, compressive sensing (CS) approach is employed for direction-of-arrival (DOA) estimation by solving an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">l</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> norm minimization problem. The theoretical propositions are proved and numerical simulations are performed to demonstrate the superior performance of the proposed GNA family and the DOA estimation.

Seismic control of multidegree‐of‐freedom structures using a concentratedly arranged tuned viscous mass damper

AbstractConnecting a flexible supporting element to an inerter arranged in parallel with a viscous element yields a tuned‐mass damper‐like system, designated as a tuned viscous mass damper (TVMD). The advantage of a TVMD is that it exploits the flexibility of the supporting member, which is usually considered to compromise the energy‐dissipating performance, and the inerter and soft spring form a supplemental oscillator to enhance the damping performance with resonance to the primary structure. The fixed‐point method for the optimal design of a single‐degree‐of‐freedom structure containing a TVMD is further expanded to a multidegree‐of‐freedom structure, in which a TVMD is arranged concentratedly. Furthermore, approximated closed‐form formulae for a concentratedly arranged TVMD are derived under the assumption that the primary structure is undamped, remains in an elastic range, and the target mode dominates the response of the structure. An analytical example illustrates that installing a TVMD spanning three stories in a concentrated manner based on the proposed design methods ensures the efficiency of the damping system, which demonstrates a damping effect similar to that of stiffness‐proportionally distributed TVMDs with less demand for inertance and total control force, thus resulting in a lower cost.

RCM adjustment for a double-parallelogram based RCM mechanism used for MIS robots

The inevitable errors in the manufacturing, assembly, and testing of a remote center-of-motion (RCM) mechanism lead to the erroneous link parameters which deviate its geometry. Consequently, the motion, as well as the force, become non-zero at the entry port to the patient’s body which is undesirable. To address this issue, the current work first presents the accurate kinematic model of the RCM of an exemplary double-parallelogram-based RCM mechanism. Thereafter, it introduces the RCM adjustment concept and a flexure-based compliant mechanism to nullify/minimize the said deviation. For the analytical design of the flexure element, this paper makes the required design calculations and performs the finite element analysis. It is followed by the disclosure of the RCM Adjustment System and a systematized method of RCM adjustment for a mechanically constrained RCM device. The devised system is based on the prescribed compliant mechanism design and is advantageous, over the traditional RCM adjustments. The potential of the proposed concept lies in the fact that it is not limited to the adopted mechanism only rather, it is extendable to other mechanisms as well which was missing in the prior art. In addition, it offers a more simplified and economical design. Further, an initial prototype of the exemplary mechanism is manufactured using laser micromachining and rapid prototyping techniques. Both analytical as well as physical validations have been performed which proved the efficacy of the proposed kinematic modeling concept. Furthermore, the prototype of the introduced RCM Adjustment System is manufactured as a single-piece design which demonstrated its effectiveness. The preferred embodiment of the same is the said double-parallelogram-based RCM mechanism which is most widely used for robot-assisted minimally invasive surgery (RAMIS). It is designed in a SolidWorks environment and manufactured using Al6101-T6 and SS304 as link material, and a variety of standard elements.

Risk aversion and flexibility options in electricity markets

Flexibility options, such as demand response, energy storage and interconnection, have the potential to reduce variation in electricity prices between different future scenarios, thereby reducing investment risk. Investing in flexibility options can also lower the need for generation capacity. However, there are complex interactions between different flexibility options. In this paper, we investigate the interactions between flexibility and investment risk in electricity markets. In particular, we focus on the investment strategies of risk-averse decision-makers. We employ a large-scale stochastic transmission and generation expansion model of the European electricity system, providing it with uncertain future scenarios based on ENTSOs’ Ten-Year Network Development Plan. Using this model, we first investigate the effect of risk aversion on investment decisions. We find that the interplay of parameters leads to (i) more investment in a less emission-intensive energy system if planners are risk averse (hedging against CO2 price uncertainty), (ii) constant total installed capacity, regardless of the level of risk aversion (i.e. planners do not hedge against demand and uncertainties when deploying renewable energy sources) and (iii) an allocation of investments that disregards cost differences for load shedding across Europe. Second, we examine the individual effects of three flexibility elements on optimal investment levels at different levels of risk aversion: demand response, investment in additional interconnection capacity and investment in additional energy storage. We show that flexible technologies have a higher value for risk-averse decision-makers, although the effects are nonlinear. Finally, we investigate the interactions between the flexibility elements. We find that risk-averse decision-makers show a strong preference for transmission-grid expansion once flexibility is available at a low cost.

Adjoint shape optimization of Ahmed body to improve aerodynamics

Analyses are done on the bluff body of a simple ground vehicle's wake structure. A 4 million Reynolds number depending on model length. Results for various geometric configurations of the Ahmed body's flow visualization were achieved. There was a flexible geometric element called the base slant angle. Drag research found that body drag makes up about 85% of all drag. The body's rear end is where most drag is created or developed. Horseshoe vortices build a three-deck structure in wake flow. The base slant angle affects these vortices' strength, existence, and merging. Examined is the applicability of these phenomena to actual ground vehicles. To reduce drag and enhance aerodynamics, the body's shape was modified using the adjoint approach and the adjoint shape optimization tool in ANSYS Fluent. In this study, we found that by changing the tail-end vortex structure and flow separation at the rear part of the vehicle, the optimized back shape or rear slant design of the body provides better flow separation that results in better pressure recovery and reduces drag by roughly 7 to 10 percent, respectively. The comparison of experimental CD values for the Ahmed body at different rear slant angles, including 12.5o, 25o, and 30o. Since it had less variance from empirical data, the computationally computed CD for a 30° base slant angle was chosen to do adjoint shape optimization. Mesh cells of less than three lakhs were used in the CFD process, and skewness quality was checked. 60 m/s of velocity was the boundary condition for the velocity inlet.

МОДЕЛЮВАННЯ РОБОТИ ПІДСИЛЕНОГО ПОПЕРЕДНЬО НАПРУЖЕНОГО ЗГИНАЛЬНОГО ДЕРЕВ’ЯНОГО ЕЛЕМЕНТУ

An undeniable disadvantage of wood when using it in construction is its excessive flexibility. One of the ways to increase the stiffness of wooden elements is to use prestressing and reinforcement with stiffer elements. The manufacturing process of pre-stressed bending elements proposed by us is simple. However, determining the necessary effort, the necessary bending of the beam to ensure reliable operation, preventing the destruction of the element is quite difficult. One of the methods of prestressing is described, namely, the method by which the beam receives internal stresses due to the release of the bending element after the action of the external load by gluing reinforced elements. The principle of such tension can be described in the following sequence: 1. We create a bend in the bending element by applying an external load to the element. 2. We reinforce the lower zone of the bending element. At the same time, we need to know under which stress-strained state the reinforced element was installed, so that its operation can be predicted. 3. We remove the applied force with which we created the bend in the flexible wooden element, while the element wants to acquire its original shape, but this will be prevented by the armature, which will absorb part of the load and leave a small bend. It was established that the level of prestressing, namely the curvature acquired by the bending element after prestressing, depends on the initial curvature of the wooden element, as well as on the area and physical and mechanical characteristics of the materials reinforcing the beam zones. To determine the prestress, it is necessary to establish the stress-deformed states of the bending element, which occur after gluing and release of the external force. At the same time, 3 levels of the stress-strain state can be distinguished. 1. At the first stage, the compressed zone is more than the stretched zone. The relative deformations of the compressed lower zone, where the material is to be attached, is the initial start for the work of the reinforced element. 2. At the second stage, the external bending moment decreases, the internal redistribution of forces takes place, in addition to the moment perceived by the compressed and stretched zone, a moment also occurs in the stretched reinforced element. 3. The third stage is characterized by the absence of an external load, and this causes a balance between the internal forces of the bending prestressed element. The equilibrium equation for three stages was obtained. When using the element as a load-bearing structure, the cross-section in the element can be with both positive and negative curvature. The peculiarities of these two stress-strain states are manifested in the change in the position of the compressed and stretched zones. In the first case, the compressed zone is located in the lower part of the element and the upper part is occupied by the stretched zone. After the curvature changes its sign from negative to positive, the upper part becomes compressed, and the lower part becomes stretched. As a result of the simulation, it is possible to conclude that the cross-section of a bending wooden element undergoes 3 main stress-deformed states during prestressing and two during its operation

Use FACTS elements to improve energy exchange between countries in response to the high penetration of variable renewable energy

Integrating Variable Renewable Energy sources (VRE) into Electric Power System (EPS) requires optimizing the synergy between VRE characteristics, PES flexibility elements, and local Electric Market operations. However, during advanced integration phases, where VRE accounts for a significant portion of the system’s energy, and in the face of stability issues caused by energy excess, cross-border energy exchange appears to be one of the most effective solutions for Energy Management. In this investigation, to highlight the role of Flexible Alternative Current Transmission Systems (FACTS) elements to ensure the required flexibility in these energy exchange operations, a modeling strategy Methodology was implemented in MATLAB and SIMULINK to design a Static Var Compensator (SVC) and simulate its connection to a high-voltage power line between Turkey and Syria, observing its response these changes in load flow. This investigation contributes to the VRE integration strategy, identifying FACTS elements as a solution to manage excess energy and achieve efficient energy exchange.

Investigation of Perturbations Arising from Temperature Shock with a Symmetrical Arrangement of Flexible Elements of a Small Spacecraft

This paper investigates the effect of a temperature shock on a small spacecraft with symmetrically arranged flexible elements. A two-dimensional thermoelasticity problem is posed. The disturbing effect of temperature shock on a small spacecraft has been determined. The assessment of the main disturbing factors arising from the temperature shock of flexible elements of a small spacecraft was carried out. Approximate dependences were obtained for the components of the displacement vector of the flexible element points. Numerical simulation was carried out for the symmetric scheme of the small spacecraft with two and four flexible elements. The dependence of the inertia force on temperature shock for the simulated small spacecraft at various initial deflections of the flexible element was constructed. Conclusions were drawn about the significance of the temperature shock influence on the dynamics of a small spacecraft. The results obtained were compared with the results of other studies and can be used in solving problems of remote sensing of the Earth and the implementation of gravity-sensitive processes on board small spacecraft.

Numerical and experimental modeling of the behavior of flexible shell elements of structures

This article is devoted to computer and experimental modeling of the behavior of flexible elements of shell structures, and the development of effective algorithms for solving emerging nonlinear boundary value problems of their calculation and optimization of parameters. At the same time, the probability of the results obtained using different approaches to the construction of a nonlinear theory is established. Their comparative analysis, error estimation, which in this case is given by calculation according to linear and corresponding nonlinear theories, is carried out. The results of calculated data and experimental studies of the behavior of real structural elements are compared.&#x0D; The results of a comparative analysis of the application of two mathematical models of deformation of flexible shell elements, obtained by direct integration of boundary value problems of shell mechanics, by the finite element method and experimental research, are presented.&#x0D; The problems of axisymmetric nonlinear bending of thin ring plates, corrugated membranes of a sinusoidal profile and bellows as a shell of rotation with a complex meridian shape are considered.&#x0D; Using the necessary optimality conditions of the principle of maximum L. S. Pontryagin obtained the results of the optimal design of a flexible corrugated membrane with a sinusoidal profile of the highest sensitivity. The results are presented in the form of tables, photos and graphs.

Economic Optimization Scheduling Based on Load Demand in Microgrids Considering Source Network Load Storage

As a large number of flexible elements such as distributed power and flexible load are connected to microgrids, the economic improvement of microgrids has become an important topic through rational energy distribution. In this paper, an economic scheduling model considering the load demand for a microgrid system under the mechanism of a peak–valley tariff is proposed. A mathematical model of the microgrid components is proposed to determine the exchange power between the microgrid and main network. Meanwhile, an improved War Strategy Optimization (WSO) algorithm is proposed to investigate three scenarios: (i) without batteries, (ii) with batteries and (iii) with batteries and demand response. Additionally, demand response optimization is carried out with the Particle Swarm Optimization (PSO) algorithm and the improved WSO is compared with four other algorithms in scenario (iii). The comparison shows that the improved WSO algorithm has a better optimization performance in solving the proposed scheduling model.

Research on the Application and Experience of Policy Tools in China's Grassroots Governance since the Reform and Opening-up --Taking Zhuanglang County of Gansu Province as an example

This paper takes 376 policy texts issued by Zhuanglang County government from 1979-2022 as the research object, and uses content analysis to sort out the use of policy tools and the history of changes in the process of grassroots governance in Zhuanglang County after reform and opening up. In terms of the types of approaches, the use of coercive tools, hybrid tools and voluntary tools in grassroots governance is comprehensive, but there is an imbalance in the use of policy tools in stages: overflow of coercive tools and lack of hybrid and voluntary tools; the types of policy tools tend to be concentrated and lack of innovation; and insufficient nesting and synergy among policy tools. In terms of evolutionary logic, the overall shift from confrontational to cooperative instruments follows a gradual contraction of coercive and confrontational elements and a steady expansion of flexible and synergistic elements. Among them, the development of voluntary policy tools is highly valued, and the participation of common subjects in policy networks becomes a new trend in grassroots social governance. In addition, through the analysis of the historical stages of policy tools, with the help of the theory of institutional change and the theory of synergetic governance, this paper summarizes the experience of the use of policy tools: paying attention to the flexibility and diversity of the use of policy tools; Pay attention to the innovation of policy tools and establish dynamic adjustment mechanism; Adhere to the logic of gradualism and the principle of bounded rationality. "History, reality and future are interlinked". The summary of experience is to better look forward to the future. We should adhere to the pertinence, comprehensiveness and synergy of the use of policy tools to achieve the modernization of grass-roots governance.

Parental Leave Policy in European Countries: A Comparative Approach Using Cluster Analysis

Abstract Currently, parental leave policy is one of the key instruments of social policy in the family sphere in many European countries. Despite the common territorial context, parental leave design may vary greatly in different European countries. In this respect, the influence of differentiative parameters of the parental leave system on the social policy results in European countries is still overlooked. Our study aims to compare parental leave policies in European countries using cluster analysis and reveal the differentiation of the results of policies related to parental leave policy in the clusters of countries. We put forward the following research questions: (1) Are groups of European countries shaped according to the characteristics of parental leave policy similar to European geographical regions? Which cluster has the largest proportion of CEE countries? (2) How different are the results of policies associated with parental leave policy in these groups of countries? As an information source, we used the International Review of Leave Policies and Research 2020, which presents data on parental leave policy in 32 European countries. As indicators for cluster analysis, we used the number of maternity, paternity, and parental leave flexibility elements. The research identified three groups of European countries varying in the number of flexibility elements in the structure of each type of leave. We concluded that leave policies in these countries are not conditioned by their geographical location but may result from their social policies. We also observed that a parental leave policy may contribute to reducing gender inequality in the country. The scientific significance of the research lies in revealing similarities and differences between parental leave policies in the context of a wide circle of European countries and in expanding existing knowledge of the public values theory in public administration.