Search Results (2,329)

This paper presents a comprehensive study of the mechanical properties of lime-based mortar in an acidic environment, employing both experimental analysis and machine learning to model techniques. Despite the extensive use of lime-based mortar in construction, particularly for the strengthening of structures as externally bonded materials, its behavior under acidic conditions remains poorly understood in the literature. This study aims to address this gap by investigating the mechanical performance of lime-based mortar under prolonged exposure to acidic environments, laying the groundwork for further research in this critical area. In the experimental phase, a commercial hydraulic lime-based mortar was subjected to varying environmental conditions, including acidic solution immersion with a pH of 3.0, distilled water immersion, and dry storage. Subsequently, the specimens were tested under flexure following exposure durations of 1000, 3000, and 5000 h. In the modeling phase, the extreme gradient boosting (XGBoost) algorithm was deployed to predict the mechanical properties of the lime-based mortar by 1000, 3000, and 5000 h of exposure. Using the experimental data, the machine learning models were trained to capture the complex relationships between the stress-displacement curve (as the output) and various environmental and mechanical properties, including density, corrosion, moisture, and exposure duration (as input features). The predictive models demonstrated remarkable accuracy and generalization (using a 4-fold cross-validation approach) capabilities (R² = 0.984 and RMSE = 0.116, for testing dataset), offering a reliable tool for estimating the mortar’s behavior over extended periods in an acidic environment. The comparative analysis demonstrated that mortar samples exposed to an acidic environment reached peak values at 3000 h of exposure, followed by a decrease in the mechanical properties with prolonged acidic exposure. In contrast, specimens exposed to distilled water and dry conditions exhibited an earlier onset of strength increase, indicating different material responses under varying environmental conditions. Full article

Predictions of the vertical location of a pitched ball (termed the passing height) when the ball arrives at an observer may be based on internal models of ball trajectory and situational cues, kinematic cues from the pitcher’s motion, and visual ball-flight cues. The informational content of ball-flight cues for judgments of vertical passing height when the ball’s launch angle is small and when situational and kinematic cues are limited is unknown. The purpose of this study was to determine whether passing heights can be judged adequately from ball-flight cues and whether judgments of passing height improve as viewing time increases under the aforementioned conditions. Twenty subjects stood 40 feet (12.19 m) from a pneumatic pitching machine that propelled tennis balls toward them at three speeds (from 53 mph (85 kph) to 77 mph (124 kph)). The ball’s launch angle was constant. The subject’s vision was blocked at 100 ms or 250 ms after pitch release. Subjects indicated the height at which they expected the ball to arrive. In the absence of explicit situational cues or kinematic cues and in the presence of a small and constant launch angle, the longer viewing time of ball-flight cues improved passing height estimates but did not result in accurate responses for the slower speeds. Full article

Background/Objectives: People with Parkinson’s disease (PwP) face high risks of bacterial infections and septic shock, often requiring inotrope treatment and mechanical ventilation. The impact of levodopa on these critical care interventions remains unclear. Methods: This retrospective cohort study analyzed data from the Taipei Medical University Clinical Research Database to explore the relationship between levodopa prescription, inotrope treatment duration, and mechanical ventilation dependence in PwP who experienced septic shock. PwP aged 45 years and older who required intensive care for septic shock were categorized into levodopa and non-levodopa groups. Results: Outcomes included inotrope treatment duration, mechanical ventilation dependence, and 3-month mortality. Among 243 PwP (116 without levodopa, 127 with levodopa), no significant difference was observed in the duration of mechanical ventilation dependence. However, levodopa prescription was associated with a significantly extended inotrope treatment duration (estimate: 3.43 days, p = 0.027). Additionally, a nonsignificant trend was identified between levodopa prescription and reduced 3-month mortality (adjusted hazard ratio = 0.67, p = 0.068). Conclusions: These findings highlight the complex interplay between Parkinson’s disease management and critical care interventions during septic shock. While levodopa may prolong inotrope use, its potential to influence survival outcomes warrants further investigation. Full article

The aim of this study was to determine the load-bearing capacity of Klein’s floors under fire conditions using analytical and numerical analyses. Analytical and numerical simulations were performed considering different structural variants of Klein’s floors. A numerical FEM model was developed in Abaqus to create temperature profiles of the beam-to-beam slabs and steel beams, and the fire load-bearing capacity of Klein’s celling after being exposed to fire for 30, 60, and 120 min was calculated analytically. The analytical method of assessing the fire load-bearing capacity of Klein’s floors uses temperature profiles, which allow for calculations to verify fire resistance in the time domain of different structural variants of Klein’s floors. (1) Introduction: The structural solutions of Klein’s floors are widely known, but no studies in the literature have addressed the mechanics of these elements under fire conditions. Both the beam-to-beam slab and steel beams are sensitive to high temperatures. Providing the required level of fire safety in buildings with Klein’s ceilings is a complex issue that requires detailed analysis. This often involves the assessment of technical and material solutions that are not currently used, and a verification of their fire resistance may be necessary to adapt existing buildings to the presently applicable technical and construction regulations. (2) Methodology: This study was prepared based on domestic and foreign sources, including standards presenting available methods for verifying the fire resistance of Klein’s ceilings in terms of their load-bearing capacity. A calculation scheme was indicated that takes into account the inter-beam slab, treated as a reinforced masonry element subjected to bending, and steel ceiling beams. In addition, this article presents an original method for determining the temperature profiles of individual elements of Klein’s ceilings, based on numerical methods, to determine their reduced values of material properties. The temperature profiles included in this study take into account both different construction variants of Klein’s ceilings and different ways of finishing the lower surface of these ceilings. The presented analytical method of fire load-bearing capacity assessment is supported by a calculation example. (3) Conclusions: The calculation methodology presented in this paper, which is part of the analysis of the fire load-bearing capacity of Klein’s ceilings, allows for a safe estimation of their durability in fire conditions. The presented temperature profiles of individual Klein’s ceiling elements allow for the verification of their fire resistance in terms of load-bearing capacity, in accordance with the literature on the subject. The temperature values of individual Klein’s ceiling elements, presented in the form of a table, depending on the fire duration, indicate that the applied structural solutions of the ceilings have a significant influence on the rate of temperature increase in the partition. Based on the conducted analyses, it was found that steel beams in an unplastered Klein’s ceiling lose their fire load-bearing capacity before the 30 min fire duration, defined by the standard temperature–time curve. The use of gypsum plaster with a thickness of at least 1.5 cm can provide fire resistance of the above elements for up to 120 min of fire duration. It was found that the quality of the plaster is important, influencing its adhesion to the lower surface of the ceiling. The fire resistance of the inter-beam slabs is significantly influenced by the temperature of their reinforcement, which largely depends on the distance of the reinforcement from the lower edge of the slab. Full article

This study introduces a radar-based model for estimating blood pressure (BP) in a touch-free manner. The model accurately detects cardiac activity, allowing for contactless and continuous BP monitoring. Cardiac motions are considered crucial components for estimating blood pressure. Unfortunately, because these movements are extremely subtle and can be readily obscured by breathing and background noise, accurately detecting these motions with a radar system remains challenging. Our approach to radar-based blood pressure monitoring in this research primarily focuses on cardiac feature extraction. Initially, an integrated-spectrum waveform is implemented. The method is derived from the short-time Fourier transform (STFT) and has the ability to capture and maintain minute cardiac activities. The integrated spectrum concentrates on energy changes brought about by short and high-frequency vibrations, in contrast to the pulse-wave signals used in previous works. Hence, the interference caused by respiration, random noise, and heart contractile activity can be effectively eliminated. Additionally, we present two approaches for estimating cardiac characteristics. These methods involve the application of a hidden semi-Markov model (HSMM) and a U-net model to extract features from the integrated spectrum. In our approach, the accuracy of extracted cardiac features is highlighted by the notable decreases in the root mean square error (RMSE) for the estimated interbeat intervals (IBIs), systolic time, and diastolic time, which were reduced by 87.5%, 88.7%, and 73.1%. We reached a comparable prediction accuracy even while our subject was breathing normally, despite previous studies requiring the subject to hold their breath. The diastolic BP (DBP) error of our model is 3.98±5.81 mmHg (mean absolute difference ± standard deviation), and the systolic BP (SBP) error is 6.52±7.51 mmHg. Full article

When inter-arrival times between events follow an exponential distribution, this implies a Poisson frequency of events, as both models assume events occur independently and at a constant average rate. However, these assumptions are often violated in real-insurance applications. When the rate at which events occur changes over time, the exponential distribution becomes unsuitable. In this paper, we study the distribution of inter-arrival times of severe storms, which exhibit substantial variability, violating the assumption of a constant average rate. A new approach is proposed for modeling severe storm recurrence patterns using a finite mixture of log-normal distributions. This approach effectively captures both frequent, closely spaced storm events and extended quiet periods, addressing the inherent variability in inter-event durations. Parameter estimation is performed using the Expectation–Maximization algorithm, with model selection validated via the Bayesian information criterion (BIC). To complement the parametric approach, Kaplan–Meier survival analysis was employed to provide non-parametric insights into storm-free intervals. Additionally, a simulation-based framework estimates storm recurrence probabilities and assesses financial risks through probable maximum loss (PML) calculations. The proposed methodology is applied to the Billion-Dollar Weather and Climate Disasters dataset, compiled by the U.S. National Oceanic and Atmospheric Administration (NOAA). The results demonstrate the model’s effectiveness in predicting severe storm recurrence intervals, offering valuable tools for managing risk in the property and casualty insurance industry. Full article

Background/Objectives: Colorectal cancer (CRC) is a leading cause of cancer-related morbidity and mortality worldwide. Sleep duration, diet, and obesity have each been identified as modifiable risk factors linked to CRC. However, their joint effect on CRC incidence is underexplored. This study investigated the association between sleep duration and CRC incidence and explored the joint effects of sleep duration, a pro-inflammatory diet, and obesity on CRC incidence in the Multiethnic Cohort (MEC). Methods: This prospective cohort study analyzed 193,027 participants from Hawaii and California enrolled in the MEC between 1993 and 1996. Sleep duration was self-reported and categorized as short (≤6 h), normal (7–8 h), or long (≥9 h). Diet was self-reported via FFQ and inflammatory potential was assessed using the energy-adjusted Dietary Inflammatory Index (E-DII). CRC cases were identified via cancer registries. Cox proportional hazards models estimated the hazard ratios (HRs) for CRC risk. Results: After 23.8 years of follow-up, 5825 CRC cases were identified. A pro-inflammatory diet combined with suboptimal sleep increased CRC risk by 12% (short sleep duration, aHR: 1.12; 95% CI: 1.02–1.24) and 22% (long sleep duration, aHR: 1.22, 95% CI: 1.05–1.43). Furthermore, long sleep duration was associated with a 10% increase in CRC risk (aHR: 1.10; 95% CI: 1.01–1.22) compared with normal sleep, while short sleep showed no significant association overall. Obese individuals with short or long sleep had significantly higher CRC risk (short sleep aHR: 1.35; 95% CI: 1.21–1.51; long sleep aHR: 1.36; 95% CI: 1.14–1.64) compared with non-obese individuals with corresponding sleep durations. Conclusions: Long sleep duration and a combination of suboptimal sleep duration and a pro-inflammatory dietary pattern or obesity amplifies the risk. Full article

Background/Objectives: Despite standard preoperative fasting guidelines, residual gastric content can persist in some patients, increasing the risk of aspiration pneumonitis. Multiple patient-specific factors may predict gastric content retention, but their predictive accuracy is limited. We hypothesized that ultrasound would more reliably identify residual gastric content compared to a comprehensive questionnaire and aimed to determine the most practical approach for risk assessment in elective surgical patients. Methods: We conducted a prospective, observational study in adult patients scheduled for elective surgery at a single center. All participants adhered to an 8 h fasting period. The primary outcome was the incidence of a “full stomach” on ultrasound. Secondary outcomes included the Perlas risk classification, comparisons of established volume estimation formulas, correlations with self-reported fasting duration, agreement between questionnaire-based predictions and ultrasound findings, and the time efficiency of each method. Multivariable logistic regression and Cohen’s kappa were used for analyses. Results: Data from 404 patients were analyzed. Despite prolonged fasting, 16.3% had a full stomach by ultrasound, suggesting incomplete gastric emptying. Early satiety and cholelithiasis significantly predicted a full stomach; prolonged fasting duration and female sex were protective. Questionnaire-based predictions demonstrated fair agreement with ultrasound (kappa = 0.327). The Michiko formula often yielded negative volumes, highlighting limitations in volume estimations. Ultrasound examination (3 min median) was faster than questionnaire completion (5 min). Conclusions: Ultrasound accurately detects residual gastric content, outperforming questionnaire-based assessments. Integrating it into routine preoperative evaluation may improve patient safety, although research is needed to refine volume estimation formulas and expand feasibility for patients with positioning limitations. Full article

This paper proposes an innovative algorithm for forecasting the motion response of floating offshore wind turbines by employing force-to-motion transfer functions and state-space models. Traditional numerical integration techniques, such as the Newmark-β method, frequently struggle with inefficiencies due to the heavy computational demands of convolution integrals in the Cummins equation. Our new method tackles these challenges by converting the problem into a system output calculation, thereby eliminating convolutions and potentially enhancing computational efficiency. The procedure begins with the estimation of force-to-motion transfer functions derived from the hydrostatic and hydrodynamic characteristics of the wind turbine. These transfer functions are then utilized to construct state-space models, which compactly represent the system dynamics. Motion responses resulting from initial conditions and wave forces are calculated using these state-space models, leveraging their poles and residues. We validated the proposed method by comparing its calculated responses to those obtained via the Newmark-β method. Initial tests on a single-degree-of-freedom (SDOF) system demonstrated that our algorithm accurately predicts motion responses. Further validation involved a numerical model of a spar-type floating offshore wind turbine, showing high accuracy in predicting responses to both regular and irregular wave conditions, closely aligning with results from conventional methods. Additionally, we assessed the efficiency of our algorithm over various simulation durations, confirming its superior performance compared to traditional time-domain methods. This efficiency is particularly advantageous for long-duration simulations. The proposed approach provides a robust and efficient alternative for predicting motion responses in floating offshore wind turbines, combining high accuracy with improved computational performance. It represents a promising tool for enhancing the development and evaluation of offshore wind energy systems. Full article

A novel concept of cold neutron source employing chessboard or staircase assemblies of high-aspect-ratio rectangular para-hydrogen moderators with well-developed and practically fully illuminated surfaces of the individual moderators is proposed. An analytic approach for calculating the brightness of para-hydrogen moderators is introduced. Because the brightness gain originates from a near-surface effect resulting from the prevailing single-collision process during thermal-to-cold neutron conversion, high-aspect-ratio rectangular cold moderators offer a significant increase, up to a factor of 10, in cold neutron brightness compared to a voluminous moderator. The obtained results are in excellent agreement with MCNP calculations. The chessboard or staircase assemblies of such moderators facilitate the generation of wide neutron beams with simultaneously higher brightness and intensity compared to a para-hydrogen-based cold neutron source made of a single moderator (either flat or voluminous) of the same cross-section. Analytic model calculations indicate that gains of up to approximately 2.5 in both brightness and intensity can be achieved compared to a source made of a single moderator of the same width. However, these gains are affected by details of the moderator–reflector assembly and should be estimated through dedicated Monte Carlo simulations, which can only be conducted for a particular neutron source and are beyond the scope of this general study. The gain reduction in our study, from a higher value to 2.5, is mostly caused by these two factors: the limited volume of the high-density thermal neutron region surrounding the reactor core or spallation target, which restricts the total length of the moderator assembly, and the finite width of moderator walls. The relatively large length of moderator assemblies results in a significant increase in pulse duration at short pulse neutron sources, making their straightforward use very problematic, though some applications are not excluded. The concept of “low-dimensionality” in moderators is explored, demonstrating that achieving a substantial increase in brightness necessitates moderators to be low-dimensional both geometrically, implying a high aspect ratio, and physically, requiring the moderator’s smallest dimension to be smaller than the characteristic scale of moderator medium (about the mean free path for thermal neutrons). This explains why additional compression of the moderator along the longest direction, effectively giving it a tube-like shape, does not result in a significant brightness increase comparable to the flattening of the moderator. Full article

Secondhand smoke affects nearly 40% of children worldwide, leading to serious health and behavioral problems. Being neurotoxic, it poses potential risks for child health and learning. In Cuba, there is limited research on the association of secondhand smoke with children’s brain health, especially in vulnerable populations like young children at home. The overall purpose of this study is two-fold. First, we determined the relationship between household smoke exposure and risks to brain health in Cuban children. Second, we analyzed the role of family environment factors, such as socio-economic status, in our estimates. Although this research represents the first investigation of its kind in Cuba, we expect to find evidence of neurotoxic associations with household smoke. We collected data between 2015 and 2018 using the medical records of 627 Cuban preschool children to explore the link between brain health indicators and exposure to tobacco smoke at home. We assessed archival reports on parental smoking, duration and frequency of exposure, and several indicators of brain health, including executive function, language development, sleep quality, and fluid intelligence. The findings indicate that exposure to tobacco smoke at home has a negative association with children’s brain health, affecting both the cognitive (executive and linguistic functions) and non-cognitive aspects (sleep quality) of child development. Continuous exposure (five to seven times per week) and transient exposure (two to three times per week) were found to be more negatively related to sleep quality than in cognitive functions, particularly in children of middle socio-economic status. This highlights the need to implement parental information campaigns in Cuba. Full article

Background/Objectives: Time estimation was investigated in 24 healthy adults, including 12 women and 12 men, before and after an exhaustive exercise. Methods: We compared the ability of estimating time intervals in the range 1 to 5 s using tasks requiring mental counting and tasks that did not allow it. Time estimation and blood lactate levels were evaluated before and at the end of the exercise. Results: We found that the perception of time intervals between 1 and 5 s was affected at the end of the exercise. The observed effects, associated with a significant increase in blood lactate levels, were different in the two types of time estimation used in the present study. When participants had to evaluate the duration of the time interval using mental counting, a significant reduction in the overestimation of time made at rest was observed at the end of exercise. On the other hand, when participants had to assess the difference in duration between two events without the possibility of mental counting, a significant deterioration in performance was observed at the end of the exercise. In both cases, no differences were seen between genders. Conclusions: It could be hypothesized that an increase in blood lactate, acting as a type of physiological arousal, could contribute to the distortion of perceived time intervals. On the other hand, it does not yet seem possible to propose a model to explain the worsening of the perception of time when mental counting is not possible. Full article

This study empirically explores the dynamic effect of MP and FP on the economic growth of Thailand from Q1:2003 to Q2:2024. In this study, data analysis was conducted using an advanced sequence of the econometric modeling approach to guarantee that the estimated results were more consistent and reliable. First, we used Bayesian additive regression trees (BART) and Bayesian variable selection (BASAD) methods to determine macro factors with the highest probabilities influencing growth, in addition to monetary and fiscal policy tools during the studied periods. Second, we used the time-varying coefficients seemingly unrelated equation (TVSURE) model to examine the economic impact of MP and FP. Last, we also employed the Markov switching regression (MSR) model not only to support the findings from the TVSURE model but also to propose policy recommendations based on regime durations and transitions tempted by MP and FP. The main results from both TVSURE and MSR reveal the following: (1) MP is more consistent with expected growth outcomes while FP is stronger when localized, (2) MP is more effective in sustaining long periods of high growth, (3) FP is significantly stronger in recovering from recessions, and (4) the coordination of MP and FP has a similar performance to MP alone but with shorter transition periods. This study makes an empirical contribution to the ongoing debate on the effectiveness of MP and FP in boosting growth and aiding in the recovery from recessions in the case of Thailand. In addition, this study not only acknowledged certain limitations but also recommended policies to sustain the Thai economy. Full article

Introduction: Inclisiran is a novel drug that employs ribonucleic acid (RNA) interference to lower the levels of the proprotein convertase subtilisin/kexin type 9 (PCSK9) protein. It has demonstrated a significant reduction in LDL cholesterol levels compared to a placebo. We aim to comprehensively evaluate the safety of using Inclisiran in patients with dyslipidemia and ASCVD or an ASCVD risk equivalent. Methods: Four electronic databases, namely, Pubmed/MEDLINE, Web of Science, Embase, and ClinicalTrials.gov, were searched from inception to June 2024 to identify relevant randomized controlled trials (RCTs) comparing safety profiles of Inclisiran and the control group. The outcomes investigated were all-cause mortality, major adverse cardiovascular events (MACEs), injection-site adverse events, new-onset or worsening type 2 diabetes mellitus (T2DM), and nasopharyngitis. The effect estimates of outcomes were assessed using the risk ratio (RR) with a 95% confidence interval (CI). Random-effects meta-analysis was conducted using the restricted maximum likelihood method. Subgroup analysis was performed based on different dosing regimens. Results: The study included 7 RCTs, enrolling 4790 patients (age 63.8 ± 9.7 years, 33.2% females) who received Inclisiran. Compared to the control group, Inclisiran use did not yield a significant effect on all-cause mortality (RR, 0.92; 95% CI, 0.54 to 1.54; I² = 0%), MACEs (RR, 0.98; 95% CI, 0.82 to 1.17; I² = 0%), nasopharyngitis (RR, 1.10; 95% CI, 0.83 to 1.45; I² = 0%), and T2DM (RR, 1.02; 95% CI, 0.85 to 1.21; I² = 0%). However, Inclisiran use demonstrated a significant increase in injection-site adverse events (RR, 6.50; 95% CI, 3.20 to 13.20; I² = 29%). Conclusions: Inclisiran use significantly increased injection-site reactions, with no increase in mortality, T2DM, or nasopharyngitis. It demonstrates a generally favorable safety profile, making it a promising option for lipid management in individuals at high cardiovascular risk, such as those with ASCVD or equivalent conditions. While it effectively improves dyslipidemia, decision-makers should be aware of an increased incidence of injection-site reactions, which, though typically mild, warrant consideration in clinical practice. Further trials are required to assess the safety of Inclisiran, particularly the association of the severity of injection-site adverse events over longer treatment durations. Full article

Extremely severe cyclonic storms over the North Indian Ocean increased by approximately 10% during the past 30 years. The climatological characteristics of tropical cyclones for 38 years were assessed over the Bay of Bengal (BoB). A total of 24 ESCSs formed over the BoB, having their genesis in the southeast BoB, and the intensity and duration of these storms have increased in recent times. The Advanced Research version of the Weather Research and Forecasting (ARW) model is utilized to simulate the five extremely severe cyclonic storms (ESCSs) over the BoB during the past two decades using the Indian Monsoon Data Assimilation and Analysis (IMDAA) data. The initial and lateral boundary conditions are derived from the IMDAA datasets with a horizontal resolution of 0.12° × 0.12°. Five ESCSs from the past two decades were considered: Sidr 2007, Phailin 2013, Hudhud 2014, Fani 2019, and Amphan 2020. The model was integrated up to 96 h using double-nested domains of 12 km and 4 km. Model performance was evaluated using the 4 km results, compared with the available observational datasets, including the best-fit data from the India Meteorological Department (IMD), the Tropical Rainfall Measuring Mission (TRMM) satellite, and the Doppler Weather Radar (DWR). The results indicated that IMDAA provided accurate forecasts for Fani, Hudhud, and Phailin regarding the track, intensity, and mean sea level pressure, aligning well with the IMD observational datasets. Statistical evaluation was performed to estimate the model skills using Mean Absolute Error (MAE), the Root Mean Square Error (RMSE), the Probability of Detection (POD), the Brier Score, and the Critical Successive Index (CSI). The calculated mean absolute maximum sustained wind speed errors ranged from 8.4 m/s to 10.6 m/s from day 1 to day 4, while mean track errors ranged from 100 km to 496 km for a day. The results highlighted the prediction of rainfall, maximum reflectivity, and the associated structure of the storms. The predicted 24 h accumulated rainfall is well captured by the model with a high POD (96% for the range of 35.6–64.4 mm/day) and a good correlation (65–97%) for the majority of storms. Similarly, the Brier Score showed a value of 0.01, indicating the high performance of the model forecast for maximum surface winds. The Critical Successive Index was 0.6, indicating the moderate model performance in the prediction of tracks. It is evident from the statistical analysis that the performance of the model is good in forecasting storm structure, intensity and rainfall. However, the IMDAA data have certain limitations in predicting the tracks due to inadequate representation of the large-scale circulations, necessitating improvement. Full article