Control Mechanisms Research Articles

Investigating the Spatio-Temporal Signatures of Language Control-Related Brain Synchronization Processes.

Language control processes allow for the flexible manipulation and access to context-appropriate verbal representations. Functional magnetic resonance imaging (fMRI) studies have localized the brain regions involved in language control processes usually by comparing high vs. low lexical-semantic control conditions during verbal tasks. Yet, the spectro-temporal dynamics of associated brain processes remain unexplored, preventing a proper understanding of the neural bases of language control mechanisms. To do so, we recorded functional brain activity using magnetoencephalography (MEG) and fMRI, while 30 healthy participants performed a silent verb generation (VGEN) and a picture naming (PN) task upon confrontation with pictures requiring low or high lexical-semantic control processes. fMRI confirmed the association between stronger language control processes and increased left inferior frontal gyrus (IFG) perfusion, while MEG revealed these controlled mechanisms to be associated with a specific sequence of early (< 500 ms) and late (> 500 ms) beta-band (de)synchronization processes within fronto-temporo-parietal areas. Particularly, beta-band modulations of event-related (de)synchronization mechanisms were first observed in the right IFG, followed by bilateral IFG and temporo-parietal brain regions. Altogether, these results suggest that beyond a specific recruitment of inferior frontal brain regions, language control mechanisms rely on a complex temporal sequence of beta-band oscillatory mechanisms over antero-posterior areas.

Altered Mitochondrial Unfolded Protein Response and Protein Quality Control promote oxidative distress in Down Syndrome brain

Down Syndrome (DS) is a genetic disorder caused by the presence of an extra copy of chromosome 21, and leading to various developmental and cognitive defects. A critical feature of DS is the occurrence of oxidative distress particularly in the brain, which exacerbates neurodevelopmental processes. Mitochondria play a crucial role in cell energy metabolism and their impairment is one of the major causes of oxidative distress in several pathologies. Hence, this study investigates mitochondrial proteostasis by the mean of the mitochondrial Unfolded Protein Response (UPRmt) and the mitochondrial protein quality control (MQC) mechanisms in the context of DS, focusing on their implications in redox homeostasis in brain development. We analyzed key UPRmt markers and mitochondrial function in the frontal cortex isolated fromTs2Cje mice, a model for DS, across different developmental stages. Our results demonstrate significant alterations in UPRmt markers, particularly at postnatal day 0 (P0) and 1 month (1M). These changes indicate early UPRmt activation, primarily driven by the ATF5/GRP75 axis, although compromised by reduced levels of other components. Impaired UPRmt correlates with decreased mitochondrial activity, evidenced by reduced oxygen consumption rates and altered expression of OXPHOS complexes. Additionally, elevated oxidative stress markers such as 3-nitrotyrosine (3-NT), 4-hydroxynonenal (HNE), and protein carbonyls (PC) were observed, linking mitochondrial dysfunction to increased oxidative damage. Defects of MQC, including disrupted biogenesis, increased fission, and the activation of mitophagy were evident mostly at P0 and 1M consistent with UPRmt activation.Principal Component Analysis revealed distinct phenotypic differences between Ts2Cje and control mice, driven by these molecular alterations. Our findings underscore the critical role of UPRmt and MQC in DS brain development, highlighting potential therapeutic targets to mitigate mitochondrial dysfunction and oxidative distress, thereby alleviating some of the neurodevelopmental and cognitive impairments associated with DS.

Innovative power sharing and secondary controls for meshed microgrids

In alternating current (AC) microgrids, the prevalent approach for controlling the power distribution between generators and loads is droop control. This decentralized technique ensures accurate power sharing; however, its utility is restricted by significant drawbacks. Notably, in scenarios involving dissimilar power sources, mismatched impedance lines, or meshed microgrids, conventional droop control fails to ensure effective reactive power sharing among inverters, often leading to notable circulating currents. Hence, the primary objective of this paper is twofold: firstly, to examine limitations inherent to conventional droop control; secondly, to introduce a robust power-sharing methodology for AC microgrids. This novel approach is specifically designed to achieve consistent sharing of active and reactive power across meshed topology microgrids. The technique considers the presence of distributed power loads and the dynamic nature of the topology. Despite the attainment of satisfactory active and reactive power sharing, deviations in voltage and frequency occasionally manifest. To address this issue, a supplementary control mechanism is proposed as a third phase. This secondary control method focuses on reinstating the microgrid's voltage and frequency to rated values, all while upholding the precision of power sharing. The efficacy of this multi-stage methodology is rigorously validated through simulations using MATLAB/Simulink and practical experimentations.

FIND BEAR: An explainable artificial intelligence platform for stages automatic recognition in pool boiling

Pool boiling heat transfer plays a critical role as a high heat flux thermal control technology in a variety of scientific and application scenarios. However, automatic identifications of pool boiling stages with non-invasive technology achieving outstanding performance is barely reported. In this paper, we develop a novel artificial intelligence (AI) platform called Boiling-stages Explainable and Automatic Recognition (BEAR) and integrate it into our own FIND Multiphysics software. Inspired by the top-down and bottom-up attentional control mechanism of the human brain, BEAR aims to mimic the cognitive and discriminative processes of human experts while giving full play to the computational advantages of personal computers. This aim is decomposed into three goals and realized by the corresponding modules forming the architecture. BEAR is effective with an identification accuracy of up to 99.1 %. It is cost-efficient as the training time of the best-performing model embedded is 9.06 s with the model’s size of 65kB. It takes only about 0.048 ∼ 0.197 s per image to perform the entire automated identification process on a personal computer with an 8-core processor. Even a small dataset with low spatial and temporal resolution, comprising 33 images of 256 × 256 pixels, can yield results that are comparable to state-of-the-art literature in the field. Moreover, BEAR provides a platform with the scalability to carry a variety of algorithms for different application purposes, which can be beneficial in facilitating innovative modeling and further deployment in future application devices.

Adaptive control techniques for improving anti-lock braking system performance in diverse friction scenarios

Anti-lock braking systems (ABS) enhance vehicle safety by preventing wheel lock-up, but their effectiveness depends on tire-road friction. Traditional braking systems struggle to maintain effective performance due to the risk of wheel lock-up on varying road surfaces, affecting vehicle stability and control. This study presents a novel method to improve ABS efficiency across varying friction conditions. The proposed approach employs a feedback control mechanism to dynamically adjust the braking force of each wheel based on the prevailing friction coefficient. Specifically, we incorporate a P-controller in the input signal and two additional P-controllers as output and input parameters for friction. By manipulating the proportional control values, key parameters such as wheel speed, stopping distance, and slip rate can be effectively managed. Notably, our investigation reveals intriguing interactions between the proportional controls, highlighting the complexity of ABS optimization. The method was evaluated through simulations across various friction conditions, comparing it to conventional ABS in terms of brake performance, stability, and stopping distances. The results indicate that the proposed method significantly enhances ABS performance across varying friction coefficients; however, additional research is warranted to address stopping distance and time issues, particularly in snowy and icy conditions.

High-Entropy Heterostructures Modulated by Oxyphilic Transition Metals for Efficient Oxygen Evolution Reaction

The unique heterostructure and multimetallic synergy of high-entropy materials (HEMs) provide them with excellent catalytic properties for the oxygen evolution reaction (OER). Research on OER electrocatalysis in HEMs is mainly focused on the variation of transition metal composition. Little attention has been paid to the changes in the kinetic behaviour of these HEMs, let alone the control mechanisms based on these changes in kinetic behaviour. Here, we demonstrate for the first time a strategy to regulate the kinetic behaviour by reconfiguring the catalyst to form HEA-HEO heterostructures through the addition of a fifth oxyphilic metal element, x (x = Sc, Ti, V, Cr). Metal elements with higher oxyphilic activity have a higher oxygen content in the catalyst during the induced reconstruction process. However, the larger oxidation component also led to unfavorable adsorption of intermediates of the OER process on the heterostructured HEA-HEO catalysts. Operando Raman analyses and real-time kinetic simulations show that the rate-determining step (RDS) on all surfaces of the FeCoNiMn-x catalysts is the formation of the reaction intermediate OOH* from adsorbed O*. On FeCoNiMnSc, FeCoNiMnTi, FeCoNiMnV, and FeCoNiMnCr, the activation energies for the formation of OOH* intermediates showed a decreasing trend. The work function of the FeCoNiMn-x catalyst in the density functional theory (DFT) calculations shows the same trend. In stability tests, FeCoNiMnCr showed a negligible loss of activity even after being exposed to an ultra-high current density of 500mAcm–2 for 112hours. This study opens up new ideas for oxophilic metals to induce structural strategies to modify high-entropy catalysts.

Fixed/preassigned-time non-chattering synchronization of nonlinear coupled Cohen-Grossberg neural networks via event-triggered control

In this paper, the studies on fixed-time and preassigned-time synchronization for a kind of nonlinear coupled Cohen-Grossberg neural networks (CGNNs) are researched by event-triggered non-chattering control. Firstly, differing from some existed fixed-time synchronization control strategies, a power-law feedback controller without sign function is adopted to achieve non-chattering control effect. To save communication and computational resources, an event-triggered mechanism (ETM) is introduced, which can naturally avoid Zeno behavior. By designing preassigned time parameters as controller parameters, the preassigned-time synchronization of dynamic networks is studied. Then, based on the designed control mechanism, sufficient conditions for fixed-time and preassigned-time synchronization of the nonlinear coupled CGNNs are given. Finally, the validity and generality of the obtained results are verified by numerical simulation.

A novel maglev μ-EDM and its signal processing for machine condition monitoring on duplex stainless steel (DSS-2205)

This article introduces an innovative servo gap control mechanism for the micro-electrical discharge machining (µ-EDM) process. Magnetic levitation serves as the foundation for innovative gap control. Here, the magnetic force (Fem) is made balanced to gravitational force (Fg) and spring restoring force (Fs) to achieve a state of equilibrium. The equilibrium state of these forces provides the essential condition for the machine’s stability and fast positioning response. The system is empowered with a dedicated direct current power source and triggered with a spring-supported actuator arm. The oscillation of the actuator arm plays a crucial role in inducing dielectric straining within the narrow interelectrode gap. Later, the machining practicability and performance were tested by conducting preliminary experiments on duplex stainless steel (DSS-2205) in deionized water. The results indicate that the material ablation rate (MAR), tool ablation rate (TAR), average surface roughness (SR) and specific energy (SE) fall within the ranges of 117.6–223.8 μg/min, 10–29 μg/min, 1.614–2.370 µm, and 0.5396–0.9356 J/µg respectively. Furthermore, the system’s stability and health were evaluated through signal processing of the voltage-ampere (V-I) characteristic. It was found that the system maintains the proper gap efficiently and stably for the manifestation of regular discharge. The proposed solution may be a good alternative for servo gap control in μ-EDM.

LitR and its quorum-sensing regulators modulate biofilm formation by Vibrio fischeri.

Quorum sensing controls numerous processes ranging from the production of virulence factors to biofilm formation. Biofilms, communities of bacteria that are attached to one another and/or a surface, are common in nature, and when they form, they can produce a quorum of bacteria. One model system to study biofilms is the bacterium Vibrio fischeri, which forms a biofilm that promotes the colonization of its symbiotic host. Many factors promote V. fischeri biofilm formation in vitro, including the symbiosis polysaccharide (SYP) and cellulose, but the role of quorum sensing is currently understudied. Recently, a quorum-sensing-dependent transcription factor, LitR, was shown to negatively influence V. fischeri biofilm formation in the context of a biofilm-overproducing strain. To better understand the importance of LitR, we identified conditions in which the impact of LitR on biofilm formation could be observed in an otherwise wild-type strain and then investigated its role and the roles of upstream quorum regulators in biofilm phenotypes. In static conditions, LitR and its upstream quorum regulators, including autoinducer synthases LuxS and AinS, contributed to control over biofilms that were both SYP and cellulose dependent. In shaking liquid conditions, LitR and AinS contributed to control over biofilms that were primarily cellulose dependent. LitR modestly inhibited cellulose transcription in a manner that depended on the transcription factor VpsR. These findings expand our understanding of LitR and the quorum-sensing pathway in the physiology of V. fischeri and illuminate negative control mechanisms that prevent robust biofilm formation by wild-type V. fischeri under laboratory conditions.IMPORTANCEQuorum sensing is a key regulatory mechanism that controls diverse phenotypes in numerous bacteria, including Vibrio fischeri. In many microbes, quorum sensing has been shown to control biofilm formation, yet in V. fischeri, the link between quorum sensing and biofilm formation has been understudied. This study fills that knowledge gap by identifying roles for the quorum sensing-controlled transcription factor, LitR, and its upstream quorum-sensing regulators, including the autoinducer synthases AinS and LuxS, in inhibiting biofilm formation under specific conditions. It also determined that LitR inhibits the transcription of genes required for cellulose biosynthesis. This work thus expands our understanding of the complex control over biofilm regulation.

Total Cost of Ownership and Evaluation of Google Cloud Resources for the ATLAS Experiment at the LHC

The ATLAS Google Project was established as part of an ongoing evaluation of the use of commercial clouds by the ATLAS Collaboration, in anticipation of the potential future adoption of such resources by WLCG grid sites to fulfil or complement their computing pledges. Seamless integration of Google cloud resources into the worldwide ATLAS distributed computing infrastructure was achieved at large scale and for an extended period of time, and hence cloud resources are shown to be an effective mechanism to provide additional, flexible computing capacity to ATLAS. For the first time a total cost of ownership analysis has been performed, to identify the dominant cost drivers and explore effective mechanisms for cost control. Network usage significantly impacts the costs of certain ATLAS workflows, underscoring the importance of implementing such mechanisms. Resource bursting has been successfully demonstrated, whilst exposing the true cost of this type of activity. A follow-up to the project is underway to investigate methods for improving the integration of cloud resources in data-intensive distributed computing environments and reducing costs related to network connectivity, which represents the primary expense when extensively utilising cloud resources.

Roles of mobile teams in tracing lost to follow–up clients: evidence from the optimization of COVID-19 vaccination uptake and routine immunization in Ekiti State

BackgroundEvidence from literature has established that tracing lost to follow-up clients is an effective strategy for complementing other mechanisms for infectious disease control like human immunodeficiency virus (HIV), tuberculosis, and other diseases such as Ebola. As a long-standing successful public health method of optimizing acceptance and/or adherence to infectious disease treatment tracing lost to follow-up clients is usually carried out by manually investigating individuals who absconded or are absent from treatments designed to manage and/or promote their health status. This study seeks to explore the role of mobile teams in tracing clients lost to follow-up for immunization.MethodsThis study was premised on a qualitative research approach to elicit information from purposively selected populations across 9 local government areas (LGA) in Ekiti state, Nigeria. Focus group discussions, in-depth interviews, and key informant interviews were the selected methods of data collection on the roles of mobile teams in tracing lost to follow–up clients for the optimization of COVID-19 and routine immunization in Ekiti state.ResultsA total of 107 healthcare workers across Ekiti state were selected to participate in this study. Our study found tracing lost to follow-up clients resulted in two major successes for health workers. These are increased awareness of COVID-19 vaccination and routine immunization, and improved vaccination coverage for both categories of vaccinees. Distance between communities, and transportation, were interdependent issues reported by health workers as challenges in the course of their duties.ConclusionOur study emphasizes the importance of onboarding and/or training health workers across all categories that are involved in the implementation of a public health program, irrespective of the existing knowledge that they may have on the concept. This study recommends that health workers across all levels, in collaboration with key players and stakeholders employ human-centered designed approaches to improve the sensitization of caregivers, and community populace on the values, benefits, and significance of the COVID-19 vaccination and routine immunization uptake.

Tilting deformation analysis and instability prediction of arch-locked-segment landslides induced by rainfall

The failure of locked-segment landslides is associated with the destruction of locked segments that exhibit an energy accumulation effect. Thus, understanding their failure mode and instability mechanism for landslide hazard prevention and control is critical. In this paper, multiple instruments, such as tilt sensors, pore water pressure gauges, moisture sensors, matrix suction sensors, resistance strain gauges, miniature earth pressure sensors, a three-dimensional (3D) laser scanner, and a camera, were used to conduct the physical model tests on the rainfall-induced arch locked-segment landslide to analyze the resulting tilting deformation and evolution mechanism. The results indicate that the tilting deformation characteristics in the locked segment are consistent with the variation in its strain, stress, hydrodynamic responses, and slope morphology, suggesting that tilting deformation can serve as a novel monitoring approach for landslide instability. Further, the tangent angle method and the tilting rate reciprocal method can be utilized to predict the landslide instability based on the landslide tilting deformation curve. The effectiveness of this method is validated in the Huangzangsi dam area, which provides theoretical foundations for understanding the catastrophic mechanism and instability prediction of arch-locked-segment landslides.

Transcriptional regulation of development by SMAX1-LIKE proteins, targets of strigolactone and karrikin/KAI2 ligand signaling.

SUPPRESSOR OF MAX2 1 (SMAX1) and SMAX1-LIKE (SMXL) proteins comprise a family of plant growth regulators that includes downstream targets of the karrikin (KAR)/KAI2 ligand (KL) and strigolactone (SL) signaling pathways. Following the perception of KAR/KL or SL signals by α/β hydrolases, some types of SMXL proteins are polyubiquitinated by an E3 ubiquitin ligase complex containing the F-box protein MORE AXILLARY GROWTH2 (MAX2)/DWARF3 (D3), and proteolyzed. Because SMXL proteins interact with TOPLESS (TPL) and TPL-related (TPR) transcriptional corepressors, SMXL degradation initiates changes in gene expression. This simplified model of SMXL regulation and function in plants must now be revised in light of recent discoveries. It has become apparent that SMXL abundance is not regulated by KAR/KL or SL alone, and that some SMXL proteins are not regulated by MAX2/D3 at all. Therefore, SMXL proteins should be considered signaling hubs that integrate multiple cues. Here we review the current knowledge of how SMXL proteins impose transcriptional regulation of plant development and environmental responses. SMXL proteins can bind DNA directly and interact with transcriptional regulators from several protein families. Multiple mechanisms of downstream genetic control by SMXL proteins have been identified recently that do not involve the recruitment of TPL/TPR, expanding the paradigm of SMXL function.

Tailoring molecular diffusion in core‐shell zeolite imidazolate framework composites realizes efficient kinetic separation of xylene isomers

The separation of xylene isomers is a critical and energy‐intensive process in the petrochemical industry, primarily due to their closely similar molecular structures and boiling points. In this work, we report the synthesis and application of a novel core‐shell zeolitic imidazolate framework (ZIF) composite, ZIF‐65@ZIF‐67, designed to significantly enhance the kinetic separation of xylene isomers through a synergistic "shell‐gated diffusion and core‐facilitated transport" strategy. The external ZIF‐67 shell selectively restricts the diffusion of larger isomers (MX and OX), while the internal ZIF‐65 core accelerates the diffusion of PX, thereby amplifying the diffusion differences among the isomers. This architecture yields remarkable improvements in both selectivity and diffusion rates, as demonstrated by vapor‐phase adsorption studies and molecular dynamics simulations. The ZIF‐65@ZIF‐67 composite exhibits up to 12.5 times higher PX/OX selectivity in liquid‐phase adsorption and 3.4 times higher dynamic selectivity in fixed‐column breakthrough experiments compared to the individual ZIF components. Theoretical simulations further corroborate the heterogeneous diffusion control mechanism, revealing the time‐dependent diffusion regulation within the core‐shell architecture. This work underscores the great potential of core‐shell MOF composites in optimizing molecular sieving processes for industrially significant separations and highlights a new route for enhancing kinetic separation efficiency in complex multicomponent systems.

Tailoring molecular diffusion in core-shell zeolite imidazolate framework composites realizes efficient kinetic separation of xylene isomers.

The separation of xylene isomers is a critical and energy-intensive process in the petrochemical industry, primarily due to their closely similar molecular structures and boiling points. In this work, we report the synthesis and application of a novel core-shell zeolitic imidazolate framework (ZIF) composite, ZIF-65@ZIF-67, designed to significantly enhance the kinetic separation of xylene isomers through a synergistic "shell-gated diffusion and core-facilitated transport" strategy. The external ZIF-67 shell selectively restricts the diffusion of larger isomers (MX and OX), while the internal ZIF-65 core accelerates the diffusion of PX, thereby amplifying the diffusion differences among the isomers. This architecture yields remarkable improvements in both selectivity and diffusion rates, as demonstrated by vapor-phase adsorption studies and molecular dynamics simulations. The ZIF-65@ZIF-67 composite exhibits up to 12.5 times higher PX/OX selectivity in liquid-phase adsorption and 3.4 times higher dynamic selectivity in fixed-column breakthrough experiments compared to the individual ZIF components. Theoretical simulations further corroborate the heterogeneous diffusion control mechanism, revealing the time-dependent diffusion regulation within the core-shell architecture. This work underscores the great potential of core-shell MOF composites in optimizing molecular sieving processes for industrially significant separations and highlights a new route for enhancing kinetic separation efficiency in complex multicomponent systems.

Distress and coping mechanisms among people with diabetes: cross-sectional assessment from an NCD screening clinic of a tertiary care hospital in North India

BackgroundOf the numerous complications encountered by people with diabetes (PWD), the effect on mental health is concerning. Within mental health, diabetes distress (DD) occurs when a patient has unfavourable emotional stress while managing their condition, which can be managed by coping strategies but are less studied together in Indian settings. So, the present study aimed to determine the proportion of DD and associated factors and coping skills among the PWD.MethodsCross-sectional study was conducted among 596 clinically stable, ambulatory PWD visiting the NCD clinic of a tertiary care centre in North India between June 2023 and January 2024 and recruited using a systematic random sampling technique. DD was the primary dependent variable assessed using the Hindi version of the Diabetes Distress Scale (DDS). Coping was assessed using a GlucoCoper scale. Independent variables included socio-demographic and clinic history variables. Bivariate analysis described the sample characteristics. Multivariable binary logistic regression analysis explored the factors affecting the DD. The study was ethically approved, and written informed consent was obtained from the patients.ResultsOf the 596 study participants, 17.4% depicted uncontrolled diabetes, while 18.1% PWD experienced moderate to severe DD, with emotional distress depicting the highest prevalence (23.8%). Significantly increased odds of living with DD in professionals compared to Clerical, shop-owners, farmers with less monthly average income (vs. the group with unstable income), tobacco users, and those with uncontrolled disease. Overall, scores for negative coping were higher than positive coping, with significant differences between the two types among the participants with DD.ConclusionsThe study underscores the complex interplay between diabetes control, distress, and coping mechanisms in patients attending an NCD screening clinic. The findings highlight the need for a holistic approach to diabetes management that addresses not only the physical aspects but also patients’ emotional and psychological well-being.

Targeted Minimum Quantity Fluid Application in Machining

The surface integrity of a machined component is crucial for its service life part. One of the main final specifications that a machined part is inspected for is the surface integrity metrics, including surface residual stresses, surface microhardness, surface roughness, and microstructure. In this paper, the cutting fluid is strategically targeted to utilize heat energy effectively in the primary, secondary, and tertiary shear zones to positively affect the surface integrity metrics and machining mechanics. In this study, a lower quantity of the cutting fluids is targeted at the high-temperature zones to reduce the machining temperatures, thereby effectively simulating the effect of a ‘flood coolant’. The cutting fluid is applied simultaneously as a targeted Minimum Quantity Fluid (MQF) on the cutting tool’s flank and rake faces to improve the surface integrity metrics and chip formation. Also, this study analyzes the effect of the cutting fluid composition, the type of cutting fluid, and the amount of fluid quantities. The machining-induced surface integrity metrics are analyzed to understand the effects of targeted minimum quantity fluid application. The impact of the targeted application of cutting fluid on machining mechanics metrics, such as cutting forces and chip formation, is analyzed. Applying a targeted MQF application at the flank face of the cutting tool leads to higher compressive subsurface principal residual stresses. The results indicate that using MQF on both the flank and rake faces simultaneously enhances the surface integrity. The effect of a cutting fluid jet on the flank face is modeled to highlight the thermophysical properties that are crucial for selecting the appropriate cutting fluid to lower the machining-induced temperatures. With targeted MQF application, the fluid jet acts as a dynamic and external chip control mechanism. Overall, effectively managing temperatures in machining could enhance subsurface residual stresses and surface roughness using various cutting fluid combinations. Also, this paper presents a targeted cutting fluid application that improves the microstructural formation, enhancing chip control and producing machined surfaces and components with better surface integrity.

Large-eddy simulations of the noise control of supersonic rectangular jets with bevelled nozzles

The bevelled nozzle is a promising noise control approach and has been tested to suppress the noise levels in supersonic circular jets, but not in rectangular jets so far. In this study, implicit large-eddy simulations are performed to analyse the noise control of supersonic rectangular jets with single- and double-bevelled nozzles. Three nozzle pressure ratios ( $NPR = 2.3$ , 3.0 and 5.0) are considered to form two over-expanded cold jets and one under-expanded cold jet, exhausted from a baseline convergent–divergent rectangular nozzle with an aspect ratio of 2.0. Results show that, with the increase of $NPR$ , the oscillation of the jet plume is switched from a symmetrical mode to a flapping mode (preferential in the minor-axis plane), then to a helical mode, together with a reduction of the screech frequency. The amplitude of the screech tone is the strongest in the flapping jet, and the turbulent mixing noise is the most prominent in the helically oscillating jet. The single-bevelled nozzle induces asymmetric shock-cell structures and deflects the jet plumes, and the double-bevelled nozzle primarily enables the enhancement of the shear-layer mixing and shortens the lengths of the jet potential cores. With the bevelled nozzles, the gross thrusts of the baseline nozzle are increased by $0.05 \sim 7.38$ %. Details on the characteristics of far-field noise in the jets with/without the bevel cuts and their noise control mechanisms are discussed using the Ffowcs Williams–Hawkings acoustic analogy, dynamic mode decomposition and spatio-temporal Fourier transformation. Results suggest that the noise control has a close relationship with the destruction of well-organized coherent structures and the suppression of upstream-propagating guided-jet modes, which interrupt the feedback mechanism accounting for the generation of screech tones in the supersonic rectangular jets.

Blockchain enabled policy-based access control mechanism to restrict unauthorized access to electronic health records

Blockchain enabled policy-based access control mechanism to restrict unauthorized access to electronic health records

Performance Evaluation of Time and Cost In The Bungur-Kedoyo Tulungagung Road Construction Project Using The Earned Value Method

Road infrastructure is essential for supporting transportation, fostering economic growth, and enhancing community mobility. However, the Bungur-Kedoyo road construction project in Tulungagung has faced challenges in time and cost management, impacting overall project performance. This study aims to evaluate the project's time and cost performance using the Earned Value Method (EVM), a robust tool that compares planned work, completed work, and actual costs to provide a comprehensive performance analysis. Data from the 25th-week project report revealed delays, with a Schedule Variance (SV) of -Rp. 315,481,514.90 and a Schedule Performance Index (SPI) of 0.970, indicating slower progress than initially planned (SPI &lt; 1). These results highlight the need for improved project scheduling and enhanced control mechanisms to mitigate delays and manage costs effectively. By identifying inefficiencies and areas requiring intervention, the study provides actionable recommendations for improving project management practices. It concludes that integrating EVM into time and cost control processes can significantly enhance project efficiency and reliability. This research contributes to advancing infrastructure development by offering insights that can be applied to similar projects, ensuring timely and cost-effective delivery while promoting sustainable growth in the road construction sector.