Control Mechanisms Research Articles

Hardware implementation of type-2 fuzzy logic control for single axis solar tracker

Solar tracker widely maximizes solar energy harvesting by maintaining a perpendicular relative position between the sun and the solar panel. Single and dual-axis solar tracker controllers are the most control mechanisms that are widely implemented. The single-axis solar tracker (SAST) is preferable between those two control mechanisms due to economic and simpler control algorithm features. Many control algorithms have been proposed to improve the performance of SAST. The conventional proportional integral derivative (PID) controller has major limitations mainly corresponding to slower response. Moreover, it cannot handle the uncertainties of the sunlight. To overcome the problem, type 2-fuzzy logic control (T2-FLC) is proposed. The single-axis solar tracker controller based on T2-FLC is applied in Arduino and implemented in the hardware environment. It was monitored that the T2-FLC provides much better responses than the conventional controllers in terms of better dynamic response and more efficiency in harvesting solar energy.

Enhancing wind power with permanent magnet synchronous generator control strategies

AbstractDue to the substantial rise in wind power generation, the direct-drive permanent magnet synchronous generator has emerged as a leading technology for efficient variable speed operation, meeting grid demands effectively. This paper presents a comparative analysis of control strategies for permanent magnet synchronous generator based wind turbine using real variable wind speed data from a 2 MW of Tetouan wind farm in Morocco. The proposed approach is based on evaluating two primary control strategies: the adaptive fuzzy-proportional-integral controller and the conventional proportional-integral controller aimed at enhancing the wind turbine's output power. The simulation performed on MATLAB-Simulink indicates that pitch control mechanisms play a crucial role in optimizing power generation, also demonstrating its ability to achieve satisfactory performance.

Microbial Synthetic Epigenetic Tools Design and Applications.

Microbial synthetic epigenetics offers significant opportunities for the design of synthetic biology tools by leveraging reversible gene control mechanisms without altering DNA sequences. However, limited understanding and a lack of technologies for thorough analysis of the mechanisms behind epigenetic modifications have hampered their utilization in biotechnological applications. In this review, we explore advancements in developing epigenetic-based synthetic gene regulatory tools at both transcriptional and post-transcriptional levels. Furthermore, we examine strategies developed to construct epigenetic-based circuits that provide controllable and stable gene regulation, aiming to boost the performance of microbial chassis cells. Finally, we discuss the current challenges and perspectives in the development of synthetic epigenetic tools.

A mathematical framework for measuring and tuning tempo in developmental gene regulatory networks.

Embryo development is a dynamic process governed by the regulation of timing and sequences of gene expression, which control the proper growth of the organism. Although many genetic programmes coordinating these sequences are common across species, the timescales of gene expression can vary significantly among different organisms. Currently, substantial experimental efforts are focused on identifying molecular mechanisms that control these temporal aspects. In contrast, the capacity of established mathematical models to incorporate tempo control while maintaining the same dynamical landscape remains less understood. Here, we address this gap by developing a mathematical framework that links the functionality of developmental programmes to the corresponding gene expression orbits (or landscapes). This unlocks the ability to find tempo differences as perturbations in the dynamical system that preserve its orbits. We demonstrate that this framework allows for the prediction of molecular mechanisms governing tempo, through both numerical and analytical methods. Our exploration includes two case studies: a generic network featuring coupled production and degradation, with a particular application to neural progenitor differentiation; and the repressilator. In the latter, we illustrate how altering the dimerisation rates of transcription factors can decouple the tempo from the shape of the resulting orbits. We conclude by highlighting how the identification of orthogonal molecular mechanisms for tempo control can inform the design of circuits with specific orbits and tempos.

The Endosomal Sorting Complex, ESCRT, has diverse roles in blood progenitor maintenance, lineage choice and immune response.

Most hematological malignancies are associated with reduced expression of one or more components of the Endosomal Sorting Complex Required for Transport (ESCRT). However, the roles of ESCRT in stem cell and progenitor maintenance are not resolved. Parsing signaling pathways in relation to the canonical role of ESCRT poses a challenge. The Drosophila hematopoietic organ, the larval lymph gland, provides a path to dissect the roles of cellular trafficking pathways such as ESCRT in blood development and maintenance. Drosophila has 13 core ESCRT components. Knockdown of individual ESCRTs showed that only Vps28 and Vp36 were required in all lymph gland progenitors. Using the well-conserved ESCRT-II complex as an example of the range of phenotypes seen upon ESCRT depletion, we show that ESCRTs have cell-autonomous as well as non-autonomous roles in progenitor maintenance and differentiation. ESCRT depletion also sensitized posterior lobe progenitors to respond to immunogenic wasp infestation. We also identify key heterotypic roles for ESCRT in position-dependent control of Notch activation to suppress crystal cell differentiation. Our study shows that the cargo sorting machinery determines the identity of progenitors and their adaptability to the dynamic microenvironment. These mechanisms for control of cell fate may tailor developmental diversity in multiple contexts.

Insights into Error Control Mechanisms in Biological Processes: Copolymerization and Enzyme-Kinetics Revisited.

The high fidelity observed in biological information processing ranging from replication to translation has stimulated significant research efforts to clarify the underlying microscopic picture. Theoretically, several approaches to analyze the error rates have been proposed. The copolymerization theory describes the addition and removal of monomers at the growing tip of a copolymer, leading to a closed set of nonlinear equations. On the other hand, enzyme-kinetics approaches formulate linear equations of biochemical networks, describing transitions between discrete chemical states. However, it is still unclear whether the error values computed by the two approaches agree. Moreover, there are conflicting interpretations on whether the error is under thermodynamic or kinetic discrimination control. In this work, we examine the error rate in persistent copying biochemical processes by specifically analyzing both theoretical approaches. The initial disagreement of the results between the two theories motivated us to rederive the formula for the error rate in the kinetic model. The error computed with the new method resulted in excellent agreement between both theoretical approaches and with Monte Carlo simulations. Furthermore, our theoretical analysis shows that the kinetic discrimination controls the error, even when the energy difference between adding the right and wrong products is very small. Our theoretical investigation gives important insights into the physical-chemical properties of complex biological processes by providing the quantitative framework to evaluate them.

The function of CozE proteins is linked to lipoteichoic acid biosynthesis in Staphylococcus aureus.

Coordinated membrane and cell wall synthesis is vital for maintaining cell integrity and facilitating cell division in bacteria. However, the molecular mechanisms that underpin such coordination are poorly understood. Here we uncover the pivotal roles of the staphylococcal proteins CozEa and CozEb, members of a conserved family of membrane proteins previously implicated in bacterial cell division, in the biosynthesis of lipoteichoic acids (LTA) and maintenance of membrane homeostasis in Staphylococcus aureus. We establish that there is a synthetic lethal relationship between CozE and UgtP, the enzyme synthesizing the LTA glycolipid anchor Glc2DAG. By contrast, in cells lacking LtaA, the flippase of Glc2DAG, the essentiality of CozE proteins was alleviated, suggesting that the function of CozE proteins is linked to the synthesis and flipping of the glycolipid anchor. CozE proteins were indeed found to modulate the flipping activity of LtaA in vitro. Furthermore, CozEb was shown to control LTA polymer length and stability. Together, these findings establish CozE proteins as novel players in membrane homeostasis and LTA biosynthesis in S. aureus.IMPORTANCELipoteichoic acids are major constituents of the cell wall of Gram-positive bacteria. These anionic polymers are important virulence factors and modulators of antibiotic susceptibility in the important pathogen Staphylococcus aureus. They are also critical for maintaining cell integrity and facilitating proper cell division. In this work, we discover that a family of membrane proteins named CozE is involved in the biosynthesis of lipoteichoic acids (LTAs) in S. aureus. CozE proteins have previously been shown to affect bacterial cell division, but we here show that these proteins affect LTA length and stability, as well as the flipping of glycolipids between membrane leaflets. This new mechanism of LTA control may thus have implications for the virulence and antibiotic susceptibility of S. aureus.

Impaired inhibitory control when processing real but not cartoon emotional faces in autistic children: Evidence from an event-related potential study.

Impaired socioemotional functioning characterizes autistic children, but does weak inhibition control underlie their socioemotional difficulty? This study addressed this question by examining whether and, if so, how inhibition control is affected by face realism and emotional valence in school-age autistic and neurotypical children. Fifty-two autistic and 52 age-matched neurotypical controls aged 10-12 years completed real and cartoon emotional face Go/Nogo tasks while event-related potentials (ERPs) were recorded. The analyses of inhibition-emotion components (i.e., N2, P3, and LPP) and a face-specific N170 revealed that autistic children elicited greater N2 while inhibiting Nogo trials and greater P3/LPP and late LPP for real but not cartoon emotional faces. Moreover, autistic children exhibited a reduced N170 to real face emotions only. Furthermore, correlation results showed that better behavioral inhibition and emotion recognition in autistic children were associated with a reduced N170. These findings suggest that neural mechanisms of inhibitory control in autistic children are less efficient and more disrupted during real face processing, which may affect their age-appropriate socio-emotional development.

Do I have symptoms of dementia - a discursive study of awareness and shame among people with advanced dementia.

This study explores the narrated experiences of individuals with advanced stages of late-onset dementia, focusing on their diagnosis awareness. Such framing is motivated by two reasons. Firstly, there is a lack of consensus regarding the prevalence of anosognosia among people with dementia. Secondly, research on anosognosia often neglects to address the important issues of shame and stigma associated with receiving a dementia diagnosis. For this qualitative study, a total of 27 participants ranging in age from 66 to 94 were involved. The data collected were analyzed using textual-oriented discourse analysis. Our findings indicated that individuals with dementia struggled to comprehend the medical terminology used to describe their experiences within biomedical standards. The interviewees utilized five negative discourses on dementia, which shaped their attitudes toward the condition and people diagnosed with it. These discourses depicted dementia as an illness, negative ageing, a devaluation, a burden, and a life tragedy. Moreover, study participants did not outright reject the diagnosis but rather negotiated its acceptance within the context of shame associated with dementia. The concept of anosognosia can serve as a mechanism of social control and stigmatization of people with dementia within the dominant biomedical discourse.

Regulatory roles of N6-methyladenosine (m6A) methylation in RNA processing and non-communicable diseases.

Post-transcriptional RNA modification is an emerging epigenetic control mechanism in cells that is important in many different cellular and organismal processes. N6-methyladenosine (m6A) is one of the most prevalent, prolific, and ubiquitous internal transcriptional alterations in eukaryotic mRNAs, making it an important topic in the field of Epigenetics. m6A methylation acts as a dynamical regulatory process that regulates the activity of genes and participates in multiple physiological processes, by supporting multiple aspects of essential mRNA metabolic processes, including pre-mRNA splicing, nuclear export, translation, miRNA synthesis, and stability. Extensive research has linked aberrations in m6A modification and m6A-associated proteins to a wide range of human diseases. However, the impact of m6A on mRNA metabolism and its pathological connection between m6A and other non-communicable diseases, including cardiovascular disease, neurodegenerative disorders, liver diseases, and cancer remains in fragmentation. Here, we review the existing understanding of the overall role of mechanisms by which m6A exerts its activities and address new discoveries that highlight m6A's diverse involvement in gene expression regulation. We discuss m6A deposition on mRNA and its consequences on degradation, translation, and transcription, as well as m6A methylation of non-coding chromosomal-associated RNA species. This study could give new information about the molecular process, early detection, tailored treatment, and predictive evaluation of human non-communicable diseases like cancer. We also explore more about new data that suggests targeting m6A regulators in diseases may have therapeutic advantages.

Real-time outage management in active distribution networks using reinforcement learning over graphs

Self-healing smart grids are characterized by fast-acting, intelligent control mechanisms that minimize power disruptions during outages. The corrective actions adopted during outages in power distribution networks include reconfiguration through switching control and emergency load shedding. The conventional decision-making models for outage mitigation are, however, not suitable for smart grids due to their slow response and computational inefficiency. Here, we present a graph reinforcement learning model for outage management in the distribution network to enhance its resilience. The distinctive characteristic of our approach is that it explicitly accounts for the underlying network topology and its variations with switching control, while also capturing the complex interdependencies between state variables (along nodes and edges) by modeling the task as a graph learning problem. Our model learns the optimal control policy for power restoration using a Capsule-based graph neural network. We validate our model on three test networks, namely the 13, 34, and 123-bus modified IEEE networks where it is shown to achieve near-optimal, real-time performance. The resilience improvement of our model in terms of loss of energy is 607.45 kWs and 596.52 kWs for 13 and 34 buses, respectively. Our model also demonstrates generalizability across a broad range of outage scenarios.

Protective Effects of Lactoferrin Treatment Against Sodium Arsenite Exposure-Induced Nephrotoxicity.

It is said that a wide range of renal functions are at risk from arsenic exposure. We examined how lactoferrin administration may mitigate inflammation, apoptosis, redox imbalance, and fibrosis in order to counteract arsenic-induced nephrotoxicity. Accordingly, male C57BL/6 mice (6weeks) were divided into six experimental groups with six mice in each group. The first and second groups were intragastrically administered normal saline and sodium arsenite (NaAsO2) at 5mg/kg body weight concentrations as the negative control (NC) and NaAsO2 groups. The third, fourth, and fifth groups were intragastrically administered lactoferrin at concentrations of 100, 200, and 400mg/kg body weight in addition to NaAsO2 at concentrations of 5mg/kg body weight. The sixth group was intragastrically administered lactoferrin at a concentration of 200mg/kg body weight with the experimental group set as the lactoferrin group. After daily drug administration for 4weeks, the lactoferrin concentrations were optimized based on the results of renal index and renal function. Histopathological, biochemical, and gene expression analyses were performed to evaluate the status of renal tissue architecture, redox imbalance, inflammation, apoptosis, and fibrosis to confirm the alleviative effect of lactoferrin treatment against the NaAsO2 exposure-induced nephrotoxicity. The results confirmed that the 200mg/kg lactoferrin treatment mitigated these arsenic effects and maintained the normal renal frameworks. Conclusively, disrupting the renal redox balance and triggering inflammation, apoptosis, along with fibrosis is a milieu that arsenic, robustly exerts its nephrotoxic effect. Lactoferrin, probably by its direct and indirect control mechanism on these said pathways, can mitigate the nephrotoxicity and preserve the normal renal health.

Observer-Based Suboptimal Controller Design for Permanent Magnet Synchronous Motors: State-Dependent Riccati Equation Controller and Impulsive Observer Approaches

Permanent Magnet Synchronous Motors (PMSMs) with high energy efficiency, reliable performance, and a relatively simple structure are widely utilised in various applications. In this paper, a suboptimal controller is proposed for PMSMs without sensors based on the state-dependent Riccati equation (SDRE) technique combined with customised impulsive observers (IOs). Here, the SDRE technique facilitates a pseudo-linearised display of the motor with state-dependent coefficients (SDCs) while preserving all its nonlinear features. Considering the risk of non-available/non-measurable states in the motor due to sensor and instrumentation costs, the SDRE is combined with IOs to estimate the PMSM speed and position states. Customised IOs are proven to be capable of obtaining quality, continuous estimates of the motor states despite the discrete format of the output signals. The simulation results in this work illustrate an accurate state estimation and control mechanism for the speed of the PMSM in the presence of load torque disturbances and reference speed changes. It is clearly shown that the SDRE-IO design is superior compared to the most popular existing regulators in the literature for sensorless speed control.

Combating Corporate Fraud in Brazil and the Potential Impact of Bill No. 2581/2023

Objective: This study aims to investigate the regulation and applicability of the whistleblower institute in Brazil, focusing on a critical analysis of existing legislation and examining the potential impact of Bill No. 2581/2023 on promoting an ethical culture in publicly traded corporations. Method: The research employs a logical deductive method to analyze legislative documents and conduct a bibliographic review of specialized literature on law and business ethics. Additionally, it incorporates illustrative case studies, such as the recent Lojas Americanas scandal, to contextualize and deepen the discussion. Results: The analysis reveals significant gaps in the legal protection and incentives for whistleblowers in Brazil, which contribute to an environment where fraudulent practices can persist due to insufficient reporting. The study identifies Bill No. 2581/2023 as a promising legislative initiative that outlines specific measures to protect whistleblowers. The bill is seen as crucial for developing a more ethical organizational culture, aligning Brazil with international anti-corruption practices, and improving the overall business environment. Conclusions: The proposed Bill No. 2581/2023, by addressing the deficiencies in legal protections and incentives for whistleblowers, has the potential to significantly enhance internal control mechanisms within companies, boost investor confidence, and foster a more stable and fair capital market. Effective whistleblower protection is essential for combating corporate fraud and fostering a transparent and ethical business environment in Brazil.

Cavitation mitigation via curvilinear barriers in centrifugal pump

Cavitation is a significant problem in hydraulic machinery that leads to the deterioration of hydraulic performance, material damage, and flow instability. While current methods partially address cavitation instability, there is a lack of comprehensive understanding of the control mechanisms. This study focuses on controlling cavitation flow instability in a centrifugal pump by proposing an active method using obstacles on the blade's surface. A low-specific speed centrifugal pump was chosen as the research object, and a three-dimensional unsteady full-flow channel numerical simulation was conducted. The findings indicate that in the absence of cavitation, the wake vortex induced by obstacles increases energy loss in the centrifugal pump, resulting in a slight drop in efficiency. However, when cavitation occurs, the obstacles effectively improve the flow field, reduce the vortex strength near the back of the blade in the flow channel, and significantly reduce the growth rate of cavitation volume. This reduction is observed in both the cavitation volume and its first derivative. Thus, the obstacles optimize the flow structure, reduce vortex strength, and slow the growth rate of cavitation. The main control mechanism involves inducing high-pressure waves to collapse cavities and improving flow transition characteristics. To solve the inverse problem of cavitation control with obstacles inside a centrifugal pump, dimensionless geometric parameters are studied to determine better suppression effects.

Self-Help for Substance Use Disorder: A Qualitative Exploration of an Exemplary Organization in Türkiye

ABSTRACT Substance use disorders (SUDs) affect the well-being of individuals and their families, reducing their quality of life. This qualitative study examines the experiences of individuals having successfully navigated recovery from SUDs and their family members’ in Türkiye. Utilizing in-depth interviews with 13 participants, it illuminates the multifaceted role of self-help groups employing the 12-step program. The findings reveal that leisure activities, personal responsibility and spiritual needs are pivotal in the recovery journey. This research underscores the importance of shared life experiences in fostering a supportive community facilitating information exchange, personal development, and motivation for change. The role models within these groups amplifies the motivation for transformative change. Additionally, sustained interaction with group members serves as a natural control mechanism, reinforcing the sobriety process. In summary, self-help groups emerge as a vital resource for both individuals in recovery and their families, offering a multi-dimensional support system that aids in this process.

The role of group (in)efficacy in controlling deviance on group cohesion and on social identity management strategies: Social control identity motivated model

The social control identity motivated (SCIM) model proposes that perceived failure of group social control mechanisms in punishing deviance increases the threat associated with the emergence of deviance in groups. Based on this assumption, this model explains the psychosocial processes involved in the consequences for social cohesion and social identity management strategies of a match or mismatch between the implemented formal social control and the mechanisms that group members expect to be implemented based on social identity motivation processes. This model explains members’ commitment to the reinforcement of ingroup social order and status quo (in case of a match), or a need to cope with perceived inefficacy of ingroup formal social control (in case of mismatch). In response to perceived inefficacy of ingroup formal social control, individuals may engage in various identity-motivated processes, including disinvestment from the ingroup, informal social control responses, or efforts to strengthen the ingroup’s normative system through social innovation or social control mechanisms reinforcement. By accounting for the interplay between formal social control mechanisms and identity motivated social control expectations, the SCIM model intends to contribute to the understanding of social identity protective strategies in response to deviance, by highlighting that (in)efficacy of group social control mechanisms shapes this dynamic. This model is justified with both direct and indirect empirical support, and we discuss the potential of the model’s applicability, as well as the need for additional research to understand determinants of each type of response, thus leaving this model open to potential refinement.

Cyber-Syndrome: Concept, Theoretical Characterization, and Control Mechanism

Cyber-Syndrome: Concept, Theoretical Characterization, and Control Mechanism

Zr-BTB nanosheets assist in optimizing the structure of forward osmosis membranes to enhance the lithium concentration performance

Recently, low-energy forward osmosis (FO) technology has been employed in the lithium concentration stage during the extraction of lithium from brine sources. The interlayer FO membrane is renowned for its exceptional structural characteristics; however, challenges remain in selecting suitable interlayer materials and exploring their control mechanisms on amine monomers. As interlayer materials, traditional 3D nanomaterials are prone to detachment, while traditional 2D materials without micropores can increase the transmission resistance of water molecules. This study introduces a novel FO membrane utilizing Zr-BTB nanosheets with 5.4 Å micropores as the interlayer material. Based on detection and simulation calculations, it was found that the increase in steric hindrance and interaction forces jointly slowed the diffusion of amine monomers in the presence of the Zr-BTB interlayer. This results in a thinner separation layer, facilitating water transport. The interlayer also plays crucial roles in preventing defective pore formation in the separation layer and assisting in intercepting salt ions. The Zr-BTB interlayer membrane exhibited a water flux of 29.14 L m−2 h−1 and a reverse salt flux of 0.16 g m−2 h−1, which are superior to those of many FO membranes reported in the field. The prepared membrane also has excellent performance in lithium concentration applications, and its separation mechanism was explored by MD simulations.

Analysis of the dynamic mechanism of trans-boundary pollution collaborative control in the Yangtze River Economic Belt

Climate change mitigation requires simultaneous reduction of carbon emissions and air pollution. This study examines the synergy between pollution reduction and carbon reduction, identifying key variables and strategies to achieve this goal. Using a Geographical Detector model and a Coupling Degree of Coordination model, 108 cities in the Yangtze River Economic Belt (YREB) are investigated. Results show that while controlling PM2.5 has been more successful than managing carbon emissions in the YREB, synergy between pollution reduction and carbon emissions increased by an average of 7.2% from 2006 to 2019. Spatial analysis reveals higher synergy in upstream areas, indicating significant spatial diversity. The impact of pollution and emission reduction synergies is influenced by societal and environmental variables, including industry structure, technological innovation, energy structure, human capital quality, and economic basis. Synergy is amplified when natural limits align with high-quality development drivers such as technical innovation and the digital economy. Recommendations include enhancing city-to-city contact, improving energy and industrial structures, and fostering technological innovation to address regional variations in synergy levels.