Slide Surface Research Articles

An Application of DC Motor Modelled Classical Sliding Mode Control with Moving Sliding Surface to Rotary Inverted Pendulum System

The rotary inverted pendulum system (RIP), which is highly favored in control applications, is examined in this work. By determining the coordinates of the Rip elements' centers of gravity, the system's total kinetic and potential energies were determined. The kinetic and potential energy expressions were used to generate the Lagrangian function. Expressions providing the system's equations of motion were discovered by taking the Lagrangian approach into consideration. The motor's equations, which will initiate the system, have also been considered. Through the use of state variables and a Matlab program, the system's pendulum angle was managed by using a moving sliding surface and the traditional sliding mode control technique. Based on the dynamics, the slip surface's slope was computed. The sliding surface's slope was computed based on the system's dynamics. The genetic algorithm was utilized to determine the ideal values for the coefficients employed in the control structure. The findings showed that the inaccuracy was roughly zero and that the pendulum angle took around 1.5 seconds to reach the intended reference value. Furthermore, it noted that the motor torque and current values are 12 Nm and 2.5 amps, respectively. The findings show that the motor values are reasonably similar to the values seen in real-world applications. Control in real-time applications won't be an issue if the motor is chosen based on these values.

Анализ рынка нейромаркетинговых технологий и оценка их роли в повышении эффективности восприятия контента

The results of a study of the dynamics of the global market of neuromarketing technologies, in particular the market of eye movement tracking technology (eyetracking), are presented. The conclusion is made about the existing positive dynamics: in recent years, the market has been showing annual growth and, according to experts, by 2032 it may reach a value of $ 3.2 billion.; as well as the high demand for neuromarketing technologies in various fields such as healthcare, retail, the gaming industry, automotive, advertising, etc., due to the growing needs of businesses in monitoring consumer behavior, uncovering subconscious motives and emotional triggers in order to adapt company strategies to the needs of the target audience. The analysis of the market structure by region is carried out: the largest market share belongs to North America, the Asia-Pacific region and Europe. The dominant regions in the eyetracking market are North America and Europe. Neuromarketing tools are applicable for conducting research and experiments in various fields and allow you to measure responses to product advertising, packaging, price, ease of use, assessment of emotional state, as well as human perception of content posted on a website, advertising surface or presentation slides. Experiments with the use of trackers make it possible to understand how a person perceives information, what he reads first of all, what he looks at. The results of existing experiments with the use of eye trackers allow you to make decisions about content and its rational placement on the surface (slides, website, advertising banners, etc.), maximizing meaningful interaction. Further research and experiments are needed to optimize marketing efforts and increase the effectiveness of interaction with consumers.

Dynamic performance of a 5-story full-scale prestressed precast space frame structure under edge and corner column failure scenarios

Progressive collapse resistance is more critical for precast concrete than cast-in-place structures. Most existing studies utilized scaled-down and quasi-static pushdown tests on substructures with rigid constraints under key member failure scenarios. However, the connection details, the spatial action of floors and the constraint stiffness of the remaining structure significantly affect the structure's progressive collapse resistance. Full-scale structural testing is the most direct method to evaluate the progressive collapse resistance of a new prefabricated structure, although it is difficult and costly to load and measure. A 2 × 2 bay 5-story full-scale frame structure was constructed according to the minimum requirements of the Code for Seismic Design of Buildings to investigate the progressive collapse resistance of a new precast, prestressed, efficiently fabricated frame (PPEFF) system. The structure's dynamic performance was analyzed by removing the 4th-floor edge column and bottom corner column. The slider and double micro-friction surface configuration proved suitable for the rapid removal of large axial force columns in a full-scale progressive collapse experiment. The layout of the full-scale structural test and the structure's dynamic responses are described. The effect of the lateral constraint stiffness and the duration of column removal on the dynamic response of the test structure were analyzed using finite element analysis. The progressive collapse resistance mechanism of the PPEFF structure was discussed. The PPEFF system remained in an elastic state and exhibited good progressive collapse resistance.

Slope Stability Analysis and Sliding Surface Search Model Based on Swedish Slice Method

Slope Stability Analysis and Sliding Surface Search Model Based on Swedish Slice Method

Characterization of Two Novel Endolysins from Bacteriophage PEF1 and Evaluation of Their Combined Effects on the Control of Enterococcus faecalis Planktonic and Biofilm Cells.

Endolysin, a bacteriophage-derived lytic enzyme, has emerged as a promising alternative antimicrobial agent against rising multidrug-resistant bacterial infections. Two novel endolysins LysPEF1-1 and LysPEF1-2 derived from Enterococcus phage PEF1 were cloned and overexpressed in Escherichia coli to test their antimicrobial efficacy against multidrug-resistant E. faecalis strains and their biofilms. LysPEF1-1 comprises an enzymatically active domain and a cell-wall-binding domain originating from the NLPC-P60 and SH3 superfamilies, while LysPEF1-2 contains a putative peptidoglycan recognition domain that belongs to the PGRP superfamily. LysPEF1-1 was active against 89.86% (62/69) of Enterococcus spp. tested, displaying a wider antibacterial spectrum than phage PEF1. Moreover, two endolysins demonstrated lytic activity against additional gram-positive and gram-negative species pretreated with chloroform. LysPEF1-1 showed higher activity against multidrug-resistant E. faecalis strain E5 than LysPEF1-2. The combination of two endolysins effectively reduced planktonic cells of E5 in broth and was more efficient at inhibiting biofilm formation and removing biofilm cells of E. faecalis JCM 7783T than used individually. Especially at 4 °C, they reduced viable biofilm cells by 4.5 log after 2 h of treatment on glass slide surfaces. The results suggest that two novel endolysins could be alternative antimicrobial agents for controlling E. faecalis infections.

Static Output Feedback Sliding Mode Control With Structured Sliding Surface Matrices

Static Output Feedback Sliding Mode Control With Structured Sliding Surface Matrices

Tribovoltaic nanogenerators based on n-n and p-p semiconductor homojunctions

Tribovoltaic nanogenerators (TVNGs) usually consist of two heterogeneous materials with disparate Fermi levels. However, TVNGs based on two same semiconductors with uniformed Fermi levels have been rarely reported, as they are believed to lack the sufficient potential difference necessary to drive tribo-induced carriers’ separation and collection, resulting in minimal or negligible electricity production. Here, tribovoltaic nanogenerators based on two homojunction semiconductors (H-TVNGs) with the same doping concentration are proposed and designed. The H-TVNGs were demonstrated to be driven by abundant surface states introduced through laser cutting at the slider boundaries and surfaces, which further lead to the bending of interface energy bands. Upon two sliders of different sizes (with different degrees of band bending) come into contact, the built-in electric field at the interface will be established and drive tribo-induced carriers, leading to the production of a direct-current (DC) electrical signal. The performance of H-TVNGs could be effectively amplified or regulated by many factors, including laser cutting power, semiconductor surface roughness, slider shape, and the interface media, etc. These compelling findings reveal innovative physics in tribovoltaic effect, offer special insights for designing high-performance TVNGs, and provide effective strategies for device output optimization.

Thermally versatile maleimide-based polymeric thin film for detection and separation of picric acid from polluted areas

2,4,6-Trinitrophenol, commonly known as picric acid, is a powerful explosive that has been used historically in military ammunition. Picric acid is extremely toxic and sensitive to friction and heat; thus, it is prone to accidental detonation at high temperatures. It is critical to detect and separate picric acid from the impacted areas. In the present study, we designed and developed a fluorescent copolymer (P1) for temperature-dependent picric acid detection. The solvatochromic and aggregation-induced emission (AIE) properties of P1 were utilized to detect picric acid at a high temperature of 40 °C (high alert level) by turn-off emission. Additionally, a polymeric thin film (F1) was fabricated by immobilizing P1 onto the surface of quartz slide. Notably, F1 retained its emissive properties across a range of temperatures (both relatively low and high alert levels), facilitated by its AIE characteristics. The portable film, F1, displayed a nanomolar sensitivity toward picric acid, making it suitable for on-site detection in aqueous media (neutral pH). Furthermore, F1 demonstrated efficient separation of picric acid from nitroaromatic explosive mixtures with a separation efficiency of 70 % over four cycles. Importantly, F1 exhibited practical utility in detecting and separating picric acid in real samples, highlighting its potential for environmental monitoring applications.

Trajectory Tracking Control of an Autonomous Vessel in the Presence of Unknown Dynamics and Disturbances

We present a proportional–integral–derivative-based controller plus an adaptive slide surface to solve the trajectory tracking control problem for a fully actuated vessel with unknown parameters perturbed by slowly varying external unknown dynamics. The controller design assumes that the vessel moves at low speed and frequency, its physical parameters are unknown, and its state is measurable. The control approach ensures error tracking convergence toward a small vicinity at the origin. We conduct the corresponding stability analysis using the Lyapunov theory and saturation functions. We tested the controller through two numerical experiments—a turning ellipse maneuver and a rest-to-rest maneuver—where the vessel parameters were unknown, and we obtained satisfactory results.

Smart and cheap assessment of microscope slide surface wettability by polysorbate 20–in aqueous buffered solutions and for increasing amounts

Smart and cheap assessment of microscope slide surface wettability by polysorbate 20–in aqueous buffered solutions and for increasing amounts

A New Adaptive Sliding Mode Reaching Law: Theoretical Design and Simulation Analysis

AbstractIn the study (Wang et al. 2014), an adaptive reaching law is developed for sliding mode control (SMC). However, a potential issue arises when the sliding mode surface slides at the neighborhood of the origin, causing the adaptive gain in the mentioned scheme to chatter repeatedly. This results in input command chattering and has a negative impact on the stability of the system. In order to address this problem caused by the adaptive gain and switching function in SMC, and to further improve convergence performance, a new adaptive reaching law is proposed. This proposed reaching law improves upon the previous adaptive gain and ensures stable operation as the new adaptive gain converges to a small neighborhood of the origin. This improvement prevents chattering and guarantees that the tracking error of the system converges within a finite time. Finally, comparative simulation experiments are conducted to demonstrate the effectiveness and superiority of the proposed reaching law.

The Sliding Surface Determination of A Deep-seated Landslide on Cisumdawu Highway, West Java, Based on The Electrical Resistivity Tomography

Sumedang is one of the regencies in West Java Province that usually experiences landslides due to its lithology, slopes, and water level conditions. Previously slow-moving landslides occurred between 2016 and February 2021, affected the new Cileunyi-Sumedang-Dawuan (Cisumdawu) Highway at Section 2, Station 21 in the North Sumedang District. This research aims to identify the causes of these landslides using a combination of geological field observation, subsurface geo-electric resistivity-based survey, and borehole drilling. A total of fourteen boreholes were drilled to collect geotechnical data from the subsurface of the researched area, including the soil material and N-SPT value. The soil hardness and resistivity were measured and compared to establish the relationship between resistivity and engineering properties. The result of the resistivity measurement showed that the percolating water zone in the permeable loose soil was located above the impermeable layer, estimated as a slip surface. The subsurface measurement and borehole data show that the lithology of the sliding surface is a layer of clay with a thickness of 5 - 12 m, the slope of the sliding surface is 20o, and the depth is between 24 - 26 m. The cover layer of the sliding surface is a layer of silty clay and gravelly clay with a thickness of 5 - 10 m. Thus, based on the data presented, installation of bore piles and groundwater level monitoring need to be done as mitigation efforts.

Sliding Mode Control for Markov Jump Singularly Perturbed Systems Under Piecewise Homogeneous Stochastic Communication Protocol.

This work involves the sliding mode control (SMC) issue for a class of Markov jump singularly perturbed systems (MJSPSs) under consideration of unmatched external disturbances and communication constraints. For the first time, the piecewise homogeneous Markov chain (MC) which depends on the system mode and the controller mode is applied to control the scheduling of stochastic communication protocol (SCP), so that the MCs in the system models, the controller and the SCP constitute a three-layer nonstationary Markov model (NMM). This model perfectly describes the different objects of the three MCs and reflects the mutual regulation among them. The critical issue is to devise an adaptive controller and a sliding surface (SS) simultaneously under SCP scheduling. By applying a standard singular sliding mode surface, an appropriate nonstationary SMC law is established to promise the accessibility of the SS and the stability of the closed-loop system (CLS), and meet the expected performance indicator. Further, using the mode-dependent Lyapunov function and piecewise homogeneous Markov model method, sufficient criteria are obtained. The specific expression of the control gain is obtained by matrix decoupling technology. Finally, a numerical simulation is furnished to testify the correctness of the conclusion.

Enhanced Adaptive Dynamic Surface Sliding Mode Control for Optimal Performance of Grid-Connected Photovoltaic Systems

This study presents an enhanced, adaptive, and dynamic surface sliding mode control (SMC), a cutting-edge method for improving grid-connected photovoltaic (PV) system performance. The suggested control approach uses dynamic SMC and adaptive approaches to enhance the robustness and efficiency of a system. Proportional–integral (PI) and SMC, two control systems for maximum power point tracking (MPPT) in PV systems, are compared in this paper. This study finds that the SMC system is a more effective and efficient MPPT approach for PV systems compared to the conventional PI control system. The SMC system’s unique feature is the capacity to stabilize grid voltage and attain a modulation index of less than one. An important component of power electronic system control is the index, which acts as a parameter representing the relationship between the output signal’s amplitude and the reference signal’s amplitude. The SMC method demonstrates improved robustness, efficiency, and stability, especially in dynamic operating settings with load and solar radiation changes. Compared to the PI control, the SMC exhibits a noteworthy 75% reduction in voltage fluctuations and an improvement in the power output of 5% to 10%. Regarding output power optimization, voltage stability, and accurate current tracking, the SMC system performs better than the PI control system. Furthermore, the SMC technique maintains a modulation index below one and guarantees grid voltage stability, both of which are essential for the efficiency and stability of power electrical systems.

Study on the Identification, Failure Mode, and Spatial Distribution of Bank Collapses after the Initial Impoundment in the Head Section of Baihetan Reservoir in Jinsha River, China

After the initial impoundment of the Baihetan Reservoir in April 2021, the water level in front of the dam rose about 200 m. The mechanical properties and effects of the bank slopes in the reservoir area changed significantly, resulting in many bank collapses. This study systematically analyzed the bank slope of the head section of the reservoir, spanning 30 km from the dam to Baihetan Bridge, through a comprehensive investigation conducted after the initial impoundment. The analysis utilized UAV flights and ground surveys to interpret the bank slope’s distribution characteristics and failure patterns. A total of 276 bank collapses were recorded, with a geohazard development density of 4.6/km. The slope gradient of 26% of the collapsed banks experienced an increase ranging from 5 to 20° after impoundment, whereas the remaining sites’ inclines remained unchanged. According to the combination of lithology and movement mode, the bank failure mode is divided into six types, which are the surface erosion type, surface collapse type, surface slide type, bedding slip type of clastic rock, toppling type of clastic rock, and cavity corrosion type of carbonate rock. It was found that the collapsed banks in the reservoir area of 85% developed in the reactivation of old landslide deposits, while 15% in the clastic and carbonate rock. This study offers guidance for the next phase of bank collapse regulations and future geohazards prevention strategies in the Baihetan Reservoir area.

Comparative Analysis of Sliding Mode Controllers for Trajectory Tracking and Vibration Reduction in a Two-Link Flexible Manipulator with Different Sliding Surfaces

Comparative Analysis of Sliding Mode Controllers for Trajectory Tracking and Vibration Reduction in a Two-Link Flexible Manipulator with Different Sliding Surfaces

The Influence of Rock Morphology and Distribution on the Bearing Capacity and the Sliding Surface of Soil–Rock Embankment

The Influence of Rock Morphology and Distribution on the Bearing Capacity and the Sliding Surface of Soil–Rock Embankment

Efficient reliability assessment of slope stability with insightful sensitivity analysis concerning the safety factor

The limit state functions (LSFs) of slope stability are nonlinear, implicit, or derived from numerical simulations, and additional surrogate models are usually used for its reliability problems. Alternatively, an efficient numerical procedure using a variant of the HLRF-BFGS algorithm is proposed to address this issue without additional surrogate models. This proposed procedure simultaneously conducts reliability assessment and sensitivity analysis concerning the safety factor by suggested calculations of partial derivatives using the finite difference method (FDM). Two highly nonlinear numerical examples are presented to validate its convergence and to investigate the step length of the FDM. Results show that the proposed procedure can get considerable accuracy while the HLRF algorithm cannot converge, and its required iterations are about 30% and 81% less than those of the limited step-size iteration algorithm. In addition, a step length not greater than 0.1 is suggested after investigations. Application to a classical two-layered slope is illustrated. Reliability results show that the proposed procedure can get the same accuracy as those of surrogate models after only 5 iterative steps. Sensitivity results show that the cohesion of the upper soil is the only sensitivity factor, and the most possible potential slide surface lies in the upper soil.

Boosting the UV photo-detecting properties of V2O5 thin films by doping In3+ doping

In recent years, optoelectronic technology has demanded the development of efficient photodetectors by layered semiconductor materials at affordable prices. Herein, we put the efforts to generate V2O5 thin films on the surface of glass slides with diverse insertion of In content (0, 1, 2, 3, 4, and 5 wt%) via cost effective nebulizer spray pyrolysis technique and examined their application in U.V. photosensing. Standard characterization techniques are used for these films to identify the cause of In dopant on its morphological, structural, and opto-electrical properties. X-ray diffraction (XRD) plots confirm the development of single-phase orthorhombic structure grown along [010] direction, without the appearance of foreign phases. Further, the dopant ingredient (In) hikes the crystallinity and crystallite sizes (36–51 nm) up to a certain threshold level (2 wt%) and decreases it for further growing In doping. The Field emission scanning electron microscope (FESEM) images display homogeneous nanorods morphology formation at all doping levels. Doping improved its photon absorption in the U.V. region, and the bandgap obtained from the absorbance spectra tuned to a lower value of 1.98 eV up to 2 wt%. All the created thin films emit intense emission bands at 475 nm and 640 nm. Characterization involving I-V measurements under 365 nm illumination at 5 V bias exhibiting commendable performance in terms of photodetector metrics (Responsivity (R) = 7.96 × 10−1 AW−1, Detectivity (D*)=3.63 × 1011 Jones and External quantum efficiency (EQE) = 186 %) for 2 % In doped V2O5. The same sample exhibits a fast-rising /falling time up to 0.6s /0.7 s, respectively. Our results may widen the field of applications in high-performance U.V. photodetector.

The Effect of Humic Substances on the Colony Growth and Conidial Germination of Entomopathogenic Fungi from the Genus Metarhizium

The development of sustainable agricultural production involves the use of new plant protection products, with low toxicity to non-target organisms and high biodegradability. The aim of this study was to investigate the effect of commercially available preparations containing humic substances, in comparison with pure humic acids, on the growth and germination of spores of entomopathogenic fungi (EPFs) from the genus Metarhizium in vitro. AmiAGRA, HumiAGRA, AlgoHUM (recommended field dose) and pure humic acids extracted from peat, brown coal and spent mushroom substrate were added to Sabouraud’s culture substrate. Observation of the growth of the colonies of the tested species of EPFs was carried out every 5 days until day 20, measuring their diameter (mm). In the second stage of the experiment, the culture medium with the addition of preparations and pure humic acids was applied in a thin layer to the surface of glass slides and an aqueous solution with spores was introduced. Observation was carried out after 24 and 48 h, and the results obtained were expressed as percentages in relation to the control. The conducted research showed that on the 20th day of the culture (on average), preparations containing humic substances had a stimulating effect, while pure acids limited the growth of the colonies of the tested isolates slightly. The growth of M. anisopliae fungal colonies was most strongly stimulated by AlgoHUM, and M. flavoviride by HumiAGRA. The share of germinated spores after 48 h of contact with the substrate was higher than after 24 h, and more spores germinated on substrates with the addition of preparations containing humic substances than on pure humic acids.