Time Parameters Research Articles

On the Model of Transport of Salt Solution in a Xylem

We consider a model for vertical lifting of an aqueous solution of salts in a xylem. We analyzed changes of movement of the considered solution depending on various parameters. We consider an analytical approach for analysis of the considered model. The approach gives a possibility to take into account changes of parameters in space and time, as well as the nonlinearity of the considered processes.

Non-invasive assessment of left ventricular hemodynamic forces in hypertrophic cardiomyopathy

Abstract Background Hemodynamic force (HDF) analysis allows non-invasive measurement of intraventricular pressure gradients, portraying cyclic spatial-temporal interaction between blood and tissues. Impaired HDFs have been implicated in early detecting of adverse cardiac remodelling and treatment response in various cardiovascular disorders, providing insights into cardiac physiology not offered by traditional cardiovascular imaging (1). Mainly explored in heart failure, HDF analysis has not been previously applied to hypertrophic cardiomyopathy (HCM). Purpose To investigate differences in systo-diastolic function in HCM patients compared to healthy controls using HDF analysis. Methods Forty patients with HCM diagnosis (20 obstructive and 20 non-obstructive) were retrospectively evaluated in comparison with 22 healthy controls. Left ventricular (LV) HDFs were derived from routine transthoracic apical 4-, 2- and 3-chamber views using a dedicated software. Apical-basal HDF curves were generated, where positive deflections represent forces directed from the LV apex to the base, whilst negative ones are directed toward the apex. Amplitude and timing parameters were derived, the latter indexed to total cardiac cycle duration. Results Table 1 shows the demographic, clinical and echocardiographic characteristics of HCM compared to controls. Patients with HCM were older, had a slower heart rate due to treatment with beta-blockers, and showed hypercontractility, as expressed by higher LV ejection fraction. Compared to controls, HCM patients showed reduced LV longitudinal force, i.e. the force during the whole cardiac cycle (4.17% [2.36-5.52] vs. 6.01% [4.73-7.78], p=0.002), shorter time interval to systolic peak (0.15 [0.12-0.16] vs. 0.19 [0.17-0.20], p <0.001), and shorter duration of LV impulse (0.29 [0.27-0.32] vs. 0.34 [0.32-0.37], p <0.001) (Figure 1). However, no differences in terms of systolic force peak (p=0.283) or LV impulse intensity (p=0.689) were detected. During the transition between systole and diastole, LV suction (i.e. the interval including late systolic deceleration and early diastolic suction) was significantly longer (0.26 [0.22-0.29] vs. 0.23 [0.21-0.25], p=0.023) but less pronounced (6.30% [4.56-8.44] vs. 8.72% [6.71-12.59], p=0.005), likely reflecting a relaxation impairment from the very beginning of diastole. Such impairment was maintained during early diastolic filling, where the amplitude of the positive deceleration flow force was severely reduced in HCM compared to controls (2.98% [1.98-4.58] vs. 7.11% [4.55-8.72], p <0.001). Conclusions HDF analysis in HCM patients revealed unique systolic and diastolic changes reflecting faster LV contraction during systole and slower and weaker LV forces during diastole. This analysis deepens our understanding of HCM mechanic abnormalities and may help assess response to innovative treatment options.

Conduction-System pacing Italian Network Group (C-SING): insights from a Nationwide Multicenter Observational Study

Abstract Background/Introduction Conduction system pacing (CSP), encompassing His bundle pacing (HBP) and left bundle branch area pacing (LBBAP), has gained prominence in treating bradycardia and heart failure in recent years. Despite its increasing utilization, data on real-world adoption of CSP are limited. Purpose The C-SING study aimed at assessing patient characteristics, implant success, procedural details, and safety of CSP when performed in routine clinical practice. Methods Periprocedural data from 27 experienced CSP centers across Italy were collected on patients undergoing CSP implantation for various indications between January 2021 and January 2024. Results The study comprised 1,317 patients (median age 78 years [interquartile range, 71-83], male 66.2%). Leading indications included atrioventricular (AV) block (40.8%), sinus node dysfunction (12.1%), atrial fibrillation with bradycardia (9.7%), AV node ablation (9.5%), and heart failure (12.5%). Pacemakers were implanted in 77.3% of patients, cardiac resynchronization devices in 21.7%, and implantable cardioverter-defibrillators in 1.0%. Stylet-driven and lumenless CSP leads were utilized in 64.7% and 35.3% of procedures, respectively. Final 12-lead ECG assessment revealed LBBAP capture in 88.7% patients, HBP in 8.4% (selective 4.2%, non-selective 4.2%), and no CSP capture in 3.0%, resulting in a 97.0% CSP lead implantation success rate. In patients with LBBAP, predominant capture types were left bundle branch pacing (19.6%), left posterior fascicular pacing (19.2%), and left septal fascicular pacing (14.8%). Comparing HBP to LBBAP, the latter showed shorter procedural time (60 minutes [45-80] vs. 70 minutes [60-95], p=0.003), but similar fluoroscopy time (6.0 minutes [3.3-10.8] vs. 6.1 minutes [4-10], p=0.735). Paced QRS duration was longer in LBBAP (118 ms [105-130]) compared to HBP (110 ms [101-122], p<0.001). LBBAP showed lower capture thresholds (0.6 V [0.5-0.9] @0.4 ms vs. 0.8 V [0.5-1.5] @1.0 ms, p<0.001) and higher R-wave sensing (10.7 mV [8-16] vs. 4.5 mV [2.4-9.9], p<0.001). The rate of periprocedural complications was higher in patients with LBBAP than HBP (7.3% vs. 1.8%, p=0.03), with the most frequent events being intraprocedural perforation into the left ventricular cavity during lead screwing (2.6%) and CSP lead dislodgment before hospital discharge (1.4%). These occurrences necessitated lead repositioning without additional complications. Conclusion CSP demonstrated feasibility as a primary pacing strategy for various indications in a real-world, multicenter setting. LBBAP, more frequently used than HBP, exhibited shorter procedural time and superior acute electrical parameters. LBBAP revealed a higher rate of minor procedural complications than HBP. Further investigations, supported by additional long-term outcome data, are essential to comprehensively assess CSP performance.

Exploring the effects of mavacamten through hemodynamic force analysis in patients with obstructive hypertrophic cardiomyopathy

Abstract Introduction Mavacamten is a first-in-class allosteric myosin inhibitor effective in relieving left ventricular (LV) outflow tract obstruction in patients with obstructive hypertrophic cardiomyopathy (oHCM). To date, however, its effect on cardiac mechanics is still unclear. Hemodynamic force (HDF) analysis represents the fluid dynamics correlate of deformation imaging, showing a greater sensitivity in detecting early mechanical abnormalities or response to treatment [1]. Purpose To explore the in vivo effect of mavacamten on cardiac mechanics in patients with HCM after a 3 year-treatment, using HDF analysis. Methods LV HDF analysis was performed in 6 patients with oHCM (representing a cohort of the MAVA-LTE study) at baseline and after 3 years of treatment. Apical 4-, 2-, and 3-chamber echocardiographic views were analysed using a dedicated and sofisticated software. Base-apex forces (where positive deflections represent a force directed from the apex to the base of LV, whilst negative ones are directed toward the LV apex) were assessed in terms of timing indexed to cardiac cycle duration. HDF curves from the 6 patients treated with macavamten were compared to those obtained from oHCM patients (n=20), non-obstructive HCM (noHCM) patients (n=20), and healthy controls (n=22). Results Figure 1 shows a different pattern of transition between diastole and systole in HCM patients compared to controls. Specifically, HCM patients exhibited an earlier onset of the systolic phase, expressed as a fusion of late diastolic deceleration and systolic thrust. This was numerically represented as a decrease in diastolic-systolic transition time, which is 0.22 [0.20-0.24] for oHCM, 0.23 [0.21-0.25] for noHCM and 0.26 [0.26-0.30] for controls (p ≤0.001 for control vs oHCM, p ≤0.01 for control vs noHCM). Additionally, HCM patients showed an increased rate of force generation. The time to systolic peak (i.e., time interval from the onset of systole to the maximum force) was reduced in HCM patients compared to controls, and was shorter in oHCM than in noHCM patients (0.13 [0.11-0.15] vs 0.16 [0.14-0.17], p ≤0.01), thus reflecting an increased clinotropism in HCM. After 3 years of mavacamten treatment, the diastolic-systolic transition time and the time to systolic peak returned to a level similar to that of healthy controls (0.30 [0.27-0.30] in mavacamten group vs 0.26 [0.26-0.30], p >0.05, and 0.21 [0.20-0.22] vs 0.19[0.17-0.20], p=0.04, respectively) (Figure 2). Conclusion HDF analysis reveals that mavacamten affects the duration of transition from diastole to systole and prolongs time from the onset to the peak in systole. These findings may explain the removal of the mechanical coupling substrate responsible for the systolic anterior movement of mitralic leaflets and the subsequent resolution of LV outflow tract obstruction by mavacamten.Distribution of time parameters

Sleep quality in glaucoma patients

The purpose of this study is to objectively assess by polysomnography total sleep time and sleep macrostructure in glaucomatous versus non-glaucomatous individuals after adjusting for possible confounding factors affecting the quality of sleep. This is an observational, prospective, single-center, case-controlled study using a sleep research database (MARS e-Cohort) collecting clinical data, comorbidities, medications, and sleep studies of glaucomatous and non-glaucomatous individuals. The diagnosis of glaucoma was confirmed with a full comprehensive ophthalmological examination including a visual field test. Total sleep time and the main sleep parameters (time spent in stages 1, 2, 3 and 4, microarousals, apnea–hypopnea index, and indices of hypoxic burden) were compared in glaucomatous and non-glaucomatous individuals after adjusting for age, anthropometric data, and comorbidities. The study included 33 glaucomatous and 66 non-glaucomatous individuals. The median total sleep time was 325 min [273; 398] for the control group and 311 min [244; 349] for the glaucoma group. After adjusting for the potential confounding factors, there was no significant difference in total sleep time (p = 0.3) and other sleep parameters between the control group and the glaucoma group. The sleep macrostructure was comparable in the glaucomatous and non-glaucomatous individuals after careful adjustment for confounders.

MUDA: dynamic geophysical and geochemical MUltiparametric DAtabase

Abstract. In this paper, the new dynamic geophysical and geochemical MUltiparametric DAtabase (MUDA) is presented. MUDA is a new infrastructure of the National Institute of Geophysics and Volcanology (INGV), published online in December 2023, with the aim of archiving and disseminating multiparametric data collected by multidisciplinary monitoring networks. MUDA is a MySQL relational database with a web interface developed in PHP, aimed at investigating possible correlations between seismic phenomena and variations in endogenous and environmental parameters in quasi real time. At present, MUDA collects data from different types of sensors such as hydrogeochemical probes for physical–chemical parameters in waters, meteorological stations, detectors of air radon concentration, diffusive flux of carbon dioxide (CO2) and seismometers belonging both to the National Seismic Network of INGV and to temporary networks installed in the framework of multidisciplinary research projects. MUDA publishes data daily, updated to the previous day, and offers the chance to view and download multiparametric time series selected for different time periods. The resultant dataset provides broad perspectives in the framework of future high-frequency and continuous multiparametric monitoring as a starting point to identify possible seismic precursors for short-term earthquake forecasting. MUDA can be accessed at https://doi.org/10.13127/muda (Massa et al., 2023).

A new integrated modelling and control of ternary pumped storage hydro power generation for small signal stability studies

Pumped storage hydro power generation (PSHPG), a reliable renewable energy source with an energy storage feature, can impart efficient damping torque to power system oscillations to improve small signal stability with appropriate modelling and additional compensation through the governor. But ternary PSHPG (T-PSHPG) has the unique feature of hydraulic short circuit (HSC) mode, where both pumping and generating modes operate simultaneously. This study presents a novel fourth-order modified Heffron Phillips (MHP) model of T-PSHPG in coordination with a multi-band Power system stabilizer (MB-PSS) employing 2-way penstock, where primary penstock circulates water from the upper reservoir to the lower reservoir through the turbine and secondary penstock divides primary penstock, thereby creating short-circuit path through the pump. Also, this model includes additional reactive power droop control to maintain the voltage profile. A new state space matrix has been developed for coordinating T-PSHPG in HSC mode with MB-PSS. The control parameters of the proposed coordinated model are set by a new multi-objective differential evolution-improved particle swam optimization (DE-IPSO) algorithm. With variable load, random solar and wind source penetrations, it has been found that the proposed model can provide adequate damping actions. The sensitivity of the proposed model has been observed by varying critical model parameters by ±50 %. For all conditions, the settling time of speed variation is within 2.672 s to 5.951 s and the minimum damping ratio lies within 0.105 to 0.455. The minimum damping ratio is 0.32 and the settling time is found to be 3.1 s for system response subject to sudden solar power variation, which has been observed by shifting system eigenvalues toward the left half of the complex plane. Time and frequency domain parameters with sensitivity analysis predict system oscillations being damped effectively with consistency for the proposed modelling and control strategy. The results are verified in real-time with OPAL-RT real-time digital simulator. It has been justified by the present study that appropriate modelling of T-PSHPG along with coordinated control action provided by MB-PSS can handle critical power system oscillations efficiently and effective damping torque can be imparted in HSC mode.

Two-stage pseudo maximum likelihood estimation of semiparametric copula-based regression models for semi-competing risks data.

We propose a two-stage estimation procedure for a copula-based model with semi-competing risks data, where the non-terminal event is subject to dependent censoring by the terminal event, and both events are subject to independent censoring. With a copula-based model, the marginal survival functions of individual event times are specified by semiparametric transformation models, and the dependence between the bivariate event times is specified by a parametric copula function. For the estimation procedure, in the first stage, the parameters associated with the marginal of the terminal event are estimated using only the corresponding observed outcomes, and in the second stage, the marginal parameters for the non-terminal event time and the copula parameter are estimated together via maximizing a pseudo-likelihood function based on the joint distribution of the bivariate event times. We derived the asymptotic properties of the proposed estimator and provided an analytic variance estimator for inference. Through simulation studies, we showed that our approach leads to consistent estimates with less computational cost and more robustness than the one-stage procedure developed in Chen YH (Lifetime Data Anal 18:36-57, 2012), where all parameters were estimated simultaneously. In addition, our approach demonstrates more desirable finite-sample performances over another existing two-stage estimation method proposed in Zhu H et al., (Commu Statistics-Theory Methods 51(22):7830-7845, 2021) . An R package PMLE4SCR is developed to implement our proposed method.

Computational Analysis of Unsteady Oscillatory Flow of Nanofluid with Variable Electric Conductivity: Gear-Generalized Differential Quadrature Approach

Abstract The present study numerically investigated the entropy production in nanofluids' dissipative unsteady oscillatory flow characterised by variable electric conductivity and magnetic heating effects. The imposition of the non-isothermal boundary condition on the oscillatory stretching sheet plays a crucial role in establishing the self-similar solution in the presence of viscous heating. An external magnetic field (uniform in space and time) is imposed perpendicular to the plane of the oscillating stretched boundary. The energy equation, incorporating viscous dissipation effects and momentum equation, is reduced to nonlinear coupled partial differential equations and numerically solved using the Gear-generalized differential quadrature scheme. The Corcione model is implemented to describe the nanofluid's effective viscosity and thermal conductivity. Furthermore, expressions for entropy production and relative irreversibility parameter (Bejan number), considering variable electric conductivity, are derived and computed based on solutions obtained from momentum and energy equations. The impacts of parameters such as magnetic parameter, variable electric conductivity parameter, Eckert number, Strouhal number, Prandtl number and temperature difference parameters on flow, heat transfer, entropy generation, and Bejan number are systematically illustrated and examined. We observed that increasing the variable electric conductivity parameters reduces the velocity profiles while improving the thermal fields. Similar behaviour is found when the strength of a magnetic field is increased. The skin friction coefficient exhibits an augmentation in response to the Eckert number, dimensionless time, Strouhal number, nanoparticle volume fraction, magnetic parameter, and variable thermal conductivity parameter. Conversely, the Nusselt number increases concerning the Strouhal number and nanoparticle volume fraction. At the same time, it declines in association with the magnetic parameter, dimensionless time, Eckert number, and variable electric conductivity parameter. Additionally, to ensure the precision and reliability of the outcomes, the numerical code undergoes a thorough validation process that involves comparing its outputs to the findings of previous available studies. This comprehensive investigation enhances our understanding of nanofluid dynamics and provides valuable insights for optimising thermal management systems across various engineering disciplines.

A novel approach to solving Euler’s nonlinear equations for a 3DOF dynamical motion of a rigid body under gyrostatic and constant torques

This research focuses on approaching a new technique to solve the rotary movement of a three degrees-of-freedom (DOF) semi-symmetric rigid body (RB) affected by a gyrostatic torque (GT) and under the influence of the RB’s constant-fixed torques (RBCFTs). The governing nonlinear differential equations (NDEs) for the RB are derived from the famous Euler’s equations, along with another system to calculate Euler’s angles, which gives an accurate solution for the RB’s position during its motion. In the case of a semi-symmetric body about its minor axis, novel analytical solutions for the RB’s angular velocities are presented in addition to the solutions of Euler’s angles. Our procedure to obtain these solutions arises through decoupling the governing NDEs into two coupled DEs, and the averaged time parameter is used. General solutions of the later DEs are presented in view of series expansions. The impact of the internal and external torques on the body’s motion is graphically simulated, which gives an overview of the periodicity of the derived solution and the effect of various values of these torques on the solution. Moreover, these simulations present other prospects for the body’s stability by analyzing them using the famous Lyapunov function. The importance of this study arises from its wide applications in our lives in many fields, such as mathematics and physics. It also holds immense potential for enhancing mechanical systems, elucidating celestial motion, and enhancing spacecraft efficiency.

Neck triangle nerve enlargement in hereditary transthyretin amyloidosis correlates with changes in the autonomic, cardiac, and gastrointestinal systems.

Hereditary transthyretin amyloidosis (ATTRv) is a hereditary disease that affects multiple bodily systems. Although sonography generally reveals enlargement of nerves in the limbs, the brachial plexus, and vagus nerve, the clinical significance of these findings remains unclear. We performed sonographic measurements of the median nerve, cervical spinal nerves at the C5-C7 level, and the vagus nerve in patients with ATTRv and healthy controls. Clinical profiles and cardiac and gastrointestinal examination results were also collected for linear regression analysis. We recruited 47 patients with ATTRv (males/females: 34/13, age: 65.6±5.3 years). The sampled segments were all significantly larger than those of the controls. In the clinical profiles, the sum of the Z scores of the neck triangle nerves (cervical spinal nerves and vagus nerve) and of all nerves (cervical spinal nerves, vagus nerve, and median nerve at the wrist) significantly correlated with the familial amyloid polyneuropathy stage, onset of autonomic nervous system (ANS) symptoms, and autonomic symptom scores. On cardiac examinations, several ultrasonography and magnetic resonance imaging parameters (primarily those that reflect heart volume) were found to be significantly correlated with the sum of the Z scores of the cervical spinal nerves but not with the Z score of the vagus nerve. In gastrointestinal evaluation, the cross-sectional area of the vagus nerve was correlated with gastric emptying time parameters on scintigraphy. Neck triangle nerve enlargement on sonography correlated with parameters related to ANS dysfunction, indicating that nerve enlargement observed on ultrasonography may serve as a potential surrogate biomarker of ATTRv.

Enhancing Vibration Control in Smart Beams: A Comparative Study of Piezoelectric-Based Controllers Under Fluid-Induced Vibrations

Smart structures with integrated piezoelectric elements play a pivotal role in mitigating vibrations across diverse applications, by safeguarding against structural damage and performance degradation. This study delves into the active control of vibrations in beams, particularly in fluid-immersed environments where hydrodynamic forces induce complex beam oscillations. The dynamic behavior of geometrically nonlinear, simply supported beams integrated with piezoelectric elements was examined. The position of the piezoelectric patch was optimized through the GA algorithm to minimize the settling time. The optimal location for the piezoelectric patch was determined in the middle of the beam. The investigation encompasses harmonic excitation forces spanning frequencies from 10[Formula: see text]Hz to 200[Formula: see text]Hz. Our study evaluates the system’s response under two critical conditions: one with the presence of external hydrodynamic forces and the other without. To achieve effective vibration control, we employ both Proportional-Derivative (PD) and Sliding Mode Controllers (SMC), optimizing their parameters for minimum settling time as an objective function. The results underscore the remarkable superiority of the SMC, reducing settling times by an impressive 50% when compared to the PD controller. Additionally, the SMC demonstrates the ability to significantly reduce control efforts, as evidenced by actuator voltage. In the context of forced vibrations, the SMC maintains its superior performance, especially at lower frequencies. However, at higher frequencies, the emergence of chattering affects the SMC’s performance, although it remains more effective than the PD controller in low-frequency scenarios. This study sheds light on the effectiveness of piezoelectric-based control strategies for smart beams, offering valuable insights into their performance under various vibration conditions. These findings hold significant promise for practical applications where vibration control is critical.

Quantitative Comparison of Color-Coded Parametric Imaging Technologies Based on Digital Subtraction and Digital Variance Angiography: A Retrospective Observational Study.

The evaluation of hemodynamic conditions in critical limb-threatening ischemia (CLTI) patients is inevitable in endovascular interventions. In this study, the performance of color-coded digital subtraction angiography (ccDSA) and the recently developed color-coded digital variance angiography (ccDVA) was compared in the assessment of key time parameters in lower extremity interventions. The observational study included 19 CLTI patients who underwent peripheral vascular intervention at our institution in 2020. Pre- and post-dilatational images were retrospectively processed and analyzed by a commercially available ccDSA software (Kinepict Medical Imaging Tool 6.0.3; Kinepict Health Ltd., Budapest, Hungary) and by the recently developed ccDVA technology. Two protocols were applied using both a 4 and 7.5 frames per second acquisition rate. Time-to-peak (TTP) parameters were determined in four pre- and poststenotic regions of interest (ROI), and ccDVA values were compared to ccDSA read-outs. The ccDVA technology provided practically the same TTP values as ccDSA (r = 0.99, R2 = 0.98, p < 0.0001). The correlation was extremely high independently of the applied protocol or the position of ROI; the r value was 0.99 (R2 = 0.98, p < 0.0001) in all groups. A similar correlation was observed in the change in passage time (r = 0.98, R2 = 0.96, p < 0.0001). The color-coded DVA technology can reproduce the same hemodynamic data as a commercially available DSA-based software; therefore, it has the potential to be an alternative decision-supporting tool in catheter labs.

Thermal performance of a hybrid nanofluid flow through a stretchable stationary disk featuring the Cattaneo-Christov heat flux theory

A hybrid nanofluid is comprised of a (Ethylene glycol) base fluid component and (Copper and Aluminium oxide) nanoparticles, and the nanoparticles are scattered inside the Ethylene glycol. Integrating nanoparticles into a base fluid (Ethylene glycol) can significantly enhance its thermal conductivity, which in turn can boost the base fluid's rate of heat transfer. In addition, the dynamics of viscous fluid together with nanoparticles is quite interesting and has a large of applications in the industrial sector. The current predominately predictive modeling investigates the flow of the hybrid nanofluid via a stretchable stationary disk in the presence of heat source/sink. A progressive modification in he energy equation is done by utilizing the Cattaneo-Christov heat flux expressions. This theory provides predictions for the features of the thermal relaxation time of the liquid on the boundary layer flow. Further, the study focuses on the features of the Lorentz force resulting from the applied of a magnetic field perpendicular to the disk. The similarity approach is used to obtained the dimensionless ordinary differential equations.The bvp4c approach in Matlab is utilized as a numerical method for the solution. All the solutions are obtained through graphical form. According to the results, the thermal profile is reduced by adjusting the thermal relaxation time parameter. Motion of the hybrid nanofluid slows down by enlarging the magnetic force parameter. Additionally, the effect of the heat source significantly increases the thermal profile. It is noted that the temperature field is enhanced in the case of a larger Lorentz force. Moreover, the increase in volume fraction concentration intensifies the thermal distribution, but the velocity is diminished due to the effect of viscosity.

Caracterización y Análisis de la Calidad del Agua en Entornos Urbanos mediante la implementación de un Sistema Embebido con Tecnología IoT

This study aims to characterize and analyze water quality in urban environments using an IoT embedded system, focusing on San Camilo’s community of Quevedo, Ecuador, where population growth has increased the demand for drinking water. An embedded system was designed to make use of a microcontroller and sensors to monitor critical water quality parameters in real time. The collected data is transmitted to a cloud platform for storage, analysis, and visualization. Spearman's correlation coefficient was preferred for statistical analysis of the data. This allowed for the identification of patterns and relationships between the variables examined. The data revealed significant associations in non-linear data, facilitating a decision regarding the development of predictive models for water management and treatment. The results demonstrate the feasibility and efficiency of using IoT technologies in the continuous monitoring of water quality, offering a scientific basis for the collection and processing of relevant data on the quality of drinking water in residential areas, providing a robust tool to monitor public health and the comfort of the inhabitants.

Cloud-Enabled Mobile-Based Approach for Enhancing Psychosis Cognitive Assessment.

The study aims to assess the feasibility of developing cognitive tools and integrating the cloud-enabled mobile-based technology into routine clinical practice for psychotic patients. Furthermore, it aims to investigate the correlation between the results obtained using developed tools and established clinical measures, offering valuable insights into tools for enhancing the accuracy, efficiency and ease of administration of cognitive evaluation. A total of 160 participants were recruited (83 outpatients with early course of schizophrenia (SZs) and 77 healthy controls [HCs]). The participants were subjected to cognitive assessments, and the data were collected by cognitive assessment digital smart tool (CADST) and PGI memory scale (PGIMS) to assess attention (ATT) and working memory (WM). Outcome measures of these parameters were digit span (score,time) for ATT and delayed recall (score,time) for WM. The total average score in HCs was significantly higher than in SZs for ATT and WM, and CADST was significantly correlated with PGIMS for evaluating ATT and WM. Furthermore, test completion times for ATT and WM were observed more in SZs although most of SZs had achieved scores as high as that of HCs. The potential of CADST as a valuable addition to the conventional cognitive assessment method is highlighted, showing promising feasibility and strong correlations with the established tool. The importance of integrating time parameters suggests broader implications for understanding cognitive function beyond conventional scoring metrics. It demonstrates the effective and accurate approach for large-scale screening of cognitive parameters in public service settings.

Nonlinear Model Predictive Control of Heaving Wave Energy Converter with Nonlinear Froude–Krylov Forces

Wave energy holds significant promise as a renewable energy source due to the consistent and predictable nature of ocean waves. However, optimizing wave energy devices is essential for achieving competitive viability in the energy market. This paper presents the application of a nonlinear model predictive controller (MPC) to enhance the energy extraction of a heaving point absorber. The wave energy converter (WEC) model accounts for the nonlinear dynamics and static Froude–Krylov forces, which are essential in accurately representing the system’s behavior. The nonlinear MPC is tested under irregular wave conditions within the power production region, where constraints on displacement and the power take-off (PTO) force are enforced to ensure the WEC’s safety while maximizing energy absorption. A comparison is made with a linear MPC, which uses a linear approximation of the Froude–Krylov forces. The study comprehensively compares power performance and computational costs between the linear and nonlinear MPC approaches. Both MPC variants determine the optimal PTO force to maximize energy absorption, utilizing (1) a linear WEC model (LMPC) for state predictions and (2) a nonlinear model (NLMPC) incorporating exact Froude–Krylov forces. Additionally, the study analyzes four controller configurations, varying the MPC prediction horizon and re-optimization time. The results indicate that, in general, the NLMPC achieves higher energy absorption than the LMPC. The nonlinear model also better adheres to system constraints, with the linear model showing some displacement violations. This paper further discusses the computational load and power generation implications of adjusting the prediction horizon and re-optimization time parameters in the NLMPC.

Comparative analysis of operative time, blood loss, and X-ray parameters: Two-dimensional navigation guided percutaneous endoscopic transforaminal discectomy vs. conventional microscopic surgery for lumbar disc herniation

PurposeThis retrospective comparative study aims to evaluate the clinical efficacy of two-dimensional (2D) navigation-guided percutaneous endoscopic transforaminal discectomy in comparison to conventional microscopic surgery for the treatment of lumbar disc herniation (LDH), based on operative time, blood loss, and X-ray examination parameters. MethodsClinical data of patients who underwent either 2D navigation-assisted endoscopic (2D-NAE) discectomy or conventional microscopic surgery for LDH were retrospectively reviewed. Baseline characteristics, perioperative data, clinical outcomes (including visual analog scale [VAS] scores, Oswestry Disability Index [ODI] scores, and Modified MacNab criteria), and complications were compared between the two groups. ResultsA total of 95 patients were included, with 80 having complete follow-up data. The 2D navigation group comprised 47 patients, while the conventional microscopic surgery group had 33 patients. Both groups showed significant improvement in VAS and ODI scores at each follow-up time point (P < 0.05). The perioperative analysis favored the 2D navigation-assisted group, with a significantly shorter operative time (42.77 ± 7.56 vs. 59.33 ± 3.30 min; p < 0.01) and lower blood loss (10.34 ± 2.24 vs. 11.55 ± 2.20 ml; p = 0.02). The number of X-ray examinations required was similar between the two groups (2.34 ± 0.48 vs. 2.39 ± 0.56; p = 0.65), and post-operative hospitalization durations were comparable (p = 0.5). Clinical efficacy, as reflected by VAS scores for legs and ODI scores, showed no significant differences between the groups. Additionally, the Modified MacNab criteria indicated similar rates of excellent and good outcomes. ConclusionBoth 2D-NAE discectomy and conventional microscopic surgery demonstrated comparable therapeutic outcomes for LDH, with favorable clinical efficacy and safety profiles. However, 2D-NAE surgery may offer additional benefits, including shorter operative times, reduced blood loss, and fewer X-ray examinations.

Grain Structure and Tensile Properties of As-Cast and Aged Pb–1.1%Sn–0.05%Ca

Abstract The effects of temperature parameters of casting procedure and aging time at room temperature on the grain structure and tensile properties of Pb–1.1%Sn–0.05%Ca alloy for positive grids of lead-acid batteries were studied by means of optical metallography, scanning electron microscopy, and tensile properties measurements. It was established that with melt or mold temperatures rising, grains in the alloy structure become larger, which causes an increase in the elongation and a decrease in the ultimate tensile strength of the alloy. Natural aging for 32 days does not noticeably change grain size but affects tensile properties of the alloy. Final ultimate tensile strength, yield strength, and Young’s modulus are found to be 2.7, 4.9, and 1.3 times higher, respectively, but the elongation is 2.4 times lower because of the precipitation of intermetallic phases.

A multi-objective reinforcement learning framework for real-time drilling optimization based on symbolic regression and perception

In the context of the global energy transition, optimizing deep-water oil and gas drilling parameters is crucial for ensuring safety while improving efficiency. Traditional methods face limitations in highly dynamic and nonlinear drilling environments, struggling to balance speed and cost-effectiveness. Furthermore, these methods rely on real-time logging-while-drilling (LWD) data for decision-making, but delays in data collection and processing hinder timely adjustments of drilling parameters, affecting decision accuracy and responsiveness. This paper proposes a multi-objective drilling parameter optimization framework, incorporating symbolic regression, time-series networks, and Markov decision processes to precisely predict ROP, formation conditions, and optimize drilling parameters in real time. Key innovations include a multi-population evolutionary symbolic regression algorithm for constructing empirical equations, the integration of variational mode decomposition (VMD) and sample entropy for data preprocessing, and multi-head self-attention time-series networks to enhance prediction accuracy. Quantile regression further estimates the range of drilling parameter adjustments. Additionally, a drilling parameter optimization deep deterministic policy gradient (DPODDPG) algorithm was developed to automate real-time parameter adjustments. Empirical analysis on the Ledong 10-1 block in the South China Sea demonstrated significant improvements: ROP increased from 54.18 m/hr to 122.17 m/hr, mechanical specific energy (MSE) decreased from 100.82 MPa to 97.78 MPa, and cost per foot reduced from 121.16 × 102 CNY/m to 51.31 × 102 CNY/m. Compared to traditional methods, the proposed framework showed clear advantages in enhancing ROP, reducing MSE, and controlling costs, further validating its superiority in complex drilling environments. This method not only significantly improves drilling efficiency and economic benefits but also adapts to complex and changing drilling conditions, showing broad application potential, particularly in challenging deep-water oil and gas drilling operations, where it can provide more efficient and reliable optimization solutions.