Search Results (216)

In this investigation, Ni_50.9Ti_49.1 wires cold rolled to 40% and straight annealed at 480 °C, 510 °C, and 550 °C, respectively, were heat treated to shape set these wires as helical springs and enhance their SME for use as electro-mechanical actuators. These spring actuators were heat treated at 350 °C, 400 °C, and 450 °C for 30, 60, and 90 min. The wires’ performance as actuators was assessed on a custom-built testing rig, which measured both the stroke and actuation time for each wire. Additionally, the wires were characterised experimentally by DSC, XRD, and nanoindentation. The final resulting properties of the R-phase transformation helical spring actuator are controlled by the competing mechanisms of dislocation annihilation, and precipitation of Ni₄Ti₃, as well as the prior thermomechanical treatment. The optimum conditions for actuator response in Ni_50.9Ti_49.1 40% cold-worked wires were a straight annealing temperature of 480 °C and shape-setting aging conditions of 450 °C for 60 min. These parameters result in the optimum combination of defect annihilation and density of precipitates, resulting in a high-stroke (56 mm), low-hysteresis (2.68 °C) actuator with an actuation time of 6 s. Full article

This study examined engine combustion characteristics of the plastic diesel produced through pyrolysis of waste plastics as an eco-friendly source of engine fuel. We extensively measured and compared the key fuel properties based on various diesel fuel standards. Distillation and hydrotreatment processes were used to improve the quality of the pyrolysis oil, resulting in distilled plastic diesel (DPD) and hydrotreated plastic diesel (HPD). DPD and HPD were blended at 10:90 and 20:80 (vol%) ratios with commercial diesel, resulting in fuel blends termed as DPD10, DPD20, HPD10, and HPD20, respectively, to analyse their engine combustion characteristics. A full-scale 4-cylinder, 4-stroke diesel engine was used in this study. There are virtually no studies available in the literature where engine combustion characteristics have been tested with both distilled and hydrotreated plastic pyrolytic oil. This study comprehensively investigated the combustion behaviours of all four fuel blends under full-load conditions and at an engine operating speed of 1500 rpm, except engine exhaust gas temperature which was measured at varying engine speeds from 1200 rpm to 2400 rpm at an interval of 300 rpm. The study found notable differences in engine combustion characteristics between the commercial diesel and plastic diesel blends under identical operating conditions. The HPD blends had higher exhaust gas temperatures (EGTs) than the DPD blends, particularly at lower blend ratios, whereas the DPD10 and HPD10 blends had higher peak cylinder pressures than DPD20 and HPD20. The HPD10 blend exhibited the highest heat release rate (HRR) of 120.41 J/°CA. The engine combustion characteristics using a full-scale engine with distilled and hydrotreated plastic diesel and their comparison are not fully studied in the literature yet. Full article

Background: Elevated global temperatures increase the risk of heat-stroke among athletes exercising in hot conditions. Japanese high school baseball tournaments occur during peak summer, raising concerns regarding heat-related health issues. We examined whether the color of footwear and legwear affects lower-limb temperature, exploring approaches to prevent heat-related health problems. Methods: Eight mannequin legs were fitted with shoes, socks, and baseball stirrup socks in white or black combinations. Plantar and shin surface temperatures were recorded for 120 min on both dirt and artificial turf at wet-bulb globe temperatures above 30 °C and compared across color combinations. Reflectance spectra of shin legwear were also measured. Results: Plantar and shin surface temperatures increased under all conditions. On the dirt field, mannequins wearing all-black gear (shoe, sock, and baseball stirrup sock) exhibited plantar temperatures exceeding 45 °C and shin temperatures over 50 °C. The highest shin temperature occurred with the white shoe/black baseball stirrup sock combination. Temperature increases were smaller for all-white items compared with all-black items. Reflectance spectra showed that white baseball stirrup socks strongly reflected both visible and infrared light. Conclusions: Footwear and legwear color significantly influence lower-limb temperature increases during baseball games in summer heat, especially when wearing all-black items. White gear may help prevent heat-related health problems and improve performance in baseball and other outdoor sports. Full article

Both epidemiological and animal model studies have revealed that heat stroke is closely related to the development or exacerbation of dementia disorders. The most common form of dementia is Alzheimer’s disease, which is characterized by the accumulation of amyloid-β protein in the central nervous system. Notably, a whole-genome transcriptome analysis of heat stroke patients has identified the increased expression of amyloid-β precursor protein gene and the activation of amyloid processing pathways. This finding provides a molecular basis for the theory that heat stroke is a risk factor for dementia disorders. Down syndrome—a common chromosomal abnormality—is also a dementia disorder that is characterized by the overexpression of amyloid-β precursor protein gene and the accumulation of amyloid-β protein. Thus, heat stroke may also develop or exacerbate Alzheimer’s disease-like dementia in Down syndrome. For individuals with Down syndrome, heat stroke is therefore not only a life-threatening risk factor but may also be a risk factor for accelerating intellectual decline. Full article

This paper investigates the effects of using 10% v/v (E10) and 30% v/v (E30) ethanol–gasoline blends on spark ignition (SI) engine fuel consumption, brake-specific fuel consumption, brake thermal efficiency, combustion parameters and exhaust gas temperature. The 30% v/v ethanol–gasoline blend was designed not to exceed the octane number (RON and MON) of the regular commercially available reference fuel (E10); therefore, the knock resistance of the reference and research fuel does not differ significantly. The tests were conducted on an AVL internal combustion engine test cell using a four-stroke, four-cylinder, turbocharged SI engine with direct injection and a compression ratio of 12.2:1. The engine was manufactured in 2022, and it is the latest commercially available version currently in production. Engine tests were conducted under stoichiometric conditions (when possible) at loads ranging from 2–20 bar brake mean effective pressure and engine speeds ranging from 1000–6000 rpm, and the fuel consumption, brake-specific fuel consumption, combustion parameters, exhaust gas temperature and brake thermal efficiency were measured using the two different ethanol–gasoline blends. Test results showed that the higher concentration ethanol–gasoline blend—due to its lower density, lower heating value and higher latent heat of vaporization—had increased fuel consumption, brake-specific fuel consumption and decreased brake thermal efficiency, while exhaust gas temperature also decreased (at 2500 rpm 12 bar BMEP, the differences were 11%, 6.6%, −0.78% and −3.7%, respectively). Peak combustion pressures were identical under the same operating conditions, but the peak combustion temperature of E30 was on average 3% lower. Full article

Background/Objectives: Global warming and concomitant extreme weather events have markedly increased the incidence of heat stroke. Heat stroke (HS) poses a substantial threat to cerebral health by triggering neuroinflammation and accelerating neurodegenerative processes. The activation of the Nod-like receptor protein 3 (NLRP3) inflammasome for interleukin-1β (IL-1β) secretion has been implicated as a critical mechanism underlying HS-related fatalities. However, the potential role of specific dietary factors to counteract heat stroke-induced neurotoxicity remains largely underexplored. We previously reported that eicosapentaenoic acid (EPA) and urolithin A (UroA), a gut metabolite of ellagic acid, effectively suppress NLRP3 inflammasome activation against metabolic or pathogenic insults. This study aimed to assess the impact of eicosapentaenoic acid (EPA), urolithin A (UroA), and their combination on mitigating heatstroke-mediated NLRP3 inflammasome activation in microglial cells. Methods: In vitro heatstroke conditions were replicated by subjecting murine BV2 microglial cells to a high temperature (41 °C) under hypoxic conditions. To achieve nutrient loading, BV2 cells were preincubated with either EPA (50 µM) or UroA (10 µM). NLRP3 inflammasome activation was evaluated by proinflammatory gene expression, caspase-1 cleavage in cells, and IL-1β secretion to the medium. The caspase-1 activation was determined using a luciferase-based inflammasome and protease activity reporter (iGLuc) assay. Results: Exposure to high temperatures under hypoxia successfully mimicked HS conditions and promoted NLRP3 inflammasome activation in BV2 cells. Both EPA and UroA substantially attenuated the heat stroke-induced priming of proinflammatory genes. More importantly, EPA and UroA demonstrated a synergistic effect in mitigating HS-induced active caspase-1 production, leading to a dramatic decrease in IL-1β secretion. This synergistic effect between EPA and UroA was further confirmed by the iGLuc reporter assay. Conclusions: Dietary enrichment with EPA and UroA precursors may constitute an efficacious strategy for mitigating heat stroke-mediated neuroinflammation and neurodegenerative diseases. Full article

To encourage the use of alternative fuels while limiting the use of fossil fuels, researchers have focused on using more environmentally friendly fuels. Furthermore, the goal is to improve engine performance to increase energy efficiency. A four-stroke, single-cylinder, diesel engine with a common rail fuel injection system runs with diesel, biodiesel, and biodiesel–alcohol fuel blends. The tests were performed using a constant engine speed of 2000 rpm and three different gas pedal positions (20%, 50% and 80%). It was found that maximum cylinder gas pressure increased in all test fuels with increased gas pedal position (GPP) and advanced injection start time. In general, the maximum heat release rate increased in blended fuels compared to diesel fuel. In addition, it was seen that advanced injection timings caused an increase in ignition delay in all fuel types. In the same test conditions, it was observed that biodiesel–alcohol fuel blends caused an increase in ignition delay by more than 10% compared to diesel fuel (D100), while shortening combustion duration (CD) by more than 10%. A decreasing trend in CO and HC emissions was observed in the use of biodiesel fuel compared to diesel fuel. With the use of biodiesel–alcohol fuel blends, CO₂ emissions tend to decrease. Advanced injection timings caused high NO emissions. Full article

Background Chronic low-back pain (LBP) is the largest contributor to disability worldwide, yet many assessments still reduce a complex, spatially distributed condition to a single 0–10 score. Body-map drawings capture location and extent of pain, but manual digitization is too slow and inconsistent for large studies or real-time telehealth. Methods Paper pain drawings from 332 adults in the multicenter COMEBACK study (four University of California sites, March 2021–June 2023) were scanned to PDFs. A Python pipeline automatically (i) rasterized PDF pages with pdf2image v1.17.0; (ii) resized each scan and delineated anterior/posterior regions of interest; (iii) registered patient silhouettes to a canonical high-resolution template using ORB key-points, Brute-Force Hamming matching, RANSAC inlier selection, and 3 × 3 projective homography implemented in OpenCV; (iv) removed template outlines via adaptive Gaussian thresholding, Canny edge detection, and 3 × 3 dilation, leaving only patient-drawn strokes; (v) produced binary masks for pain, numbness, and pins-and-needles, then stacked these across subjects to create pixel-frequency matrices; and (vi) normalized matrices with min–max scaling and rendered heat maps. RGB composites assigned distinct channels to each sensation, enabling intuitive visualization of overlapping symptom distributions and for future data analyses. Results Cohort-level maps replicated classic low-back pain hotspots over lumbar paraspinals, gluteal fold, and posterior thighs, while exposing less-recognized clusters along the lateral hip and lower abdomen. Neuropathic-leaning drawings displayed broader leg involvement than purely nociceptive patterns. Conclusions Our automated workflow converts pen-on-paper pain drawings into machine-readable digitized images and heat maps at the population scale, laying practical groundwork for spatially informed, precision management of chronic LBP. Full article

Heat stroke (HS) is a life-threatening condition that leads to neuronal injury, particularly in the prefrontal cortex, though its mechanisms remain unclear. In this study, we established a rat HS model and observed significant inflammatory responses and neuronal pyroptosis in the prefrontal cortex 6 h post-heat exposure, with the injury severity increasing over time. Mechanistically, HS activated the caspase-1/GSDMD-dependent pyroptosis pathway through NLRP3 inflammasome activation, resulting in IL-1β and IL-18 release. Additionally, HS caused a marked increase in homocysteine (Hcy) levels in both the serum and the prefrontal cortex, accompanied by reduced expression of the Hcy metabolic enzymes MTHFR and CSE, suggesting Hcy metabolism disruption. In vitro, Hcy induced pyroptosis in PC12 cells, elevating IL-1β, IL-18, and LDH levels. Notably, the NLRP3 inhibitor MCC950 mitigated this effect by reducing IL-18 and LDH release. Reducing Hcy in vivo alleviated neuronal pyroptosis and counteracted the YTHDF2-mediated decrease in NLRP3 mRNA m⁶A modification. Hcy reduced global m⁶A modification, YTHDF2 expression, and NLRP3 m⁶A modification in PC12 cells. This study reveals that the activation of a novel m⁶A-YTHDF2-NLRP3 pathway by Hcy underlies HS-induced neuronal injury, suggesting potential therapeutic targets for HS intervention. Full article

This paper presents a study aiming to provide insight into the complex flow and heat transfer processes in the exhaust manifold of a four-stroke, compression ignition engine. An experimental system has been constructed capable of capturing temperature and heat flux high-frequency signals as they develop in the exhaust pipe wall during the engine cycle, under its steady-state operation. The values of the Heat Transfer Coefficient obtained by applying the classic convection relations have been correlated in the form of a Nusselt–Reynolds number relationship for local and spatially averaged steady-state heat transfer and compared with available experimental data obtained at the same position of the exhaust manifold. It has been shown that the use of conventional steady-state heat transfer relationships for fully developed steady-state turbulent flow in pipes underpredicts heat transfer rates when compared with those experimentally observed. Periodic flow of high frequency and geometrical effects at the exhaust entrance are expected to affect the validity of the application of the classic steady-state correlations for the exhaust manifold. To overcome this problem it is developed and presented a new correlation for the time-averaged heat transfer rates. To verify the heat transfer mechanism, the thermal field of the whole engine cylinder head, including the intake and exhaust manifolds, was analyzed using FEA (Finite Element Analysis), and the results are compared and verified with available experimental data. Full article

Background/Objectives: Ischemic stroke frequently leads to somatosensory impairments and abnormal pain perception. Meanwhile, pain perception can be evoked through multiple somatosensory modalities, each mediated by distinct neural pathways. Despite this understanding, current research investigating stroke-induced alterations in pain perception across different modalities of noxious stimulation remains insufficient, particularly concerning responses to varying stimulus intensities (including both sub-threshold and supra-threshold levels). Methods: In this study (March 2023 to July 2024), we enrolled 30 ischemic stroke patients and 35 matched controls and employed two modalities of noxious stimuli (e.g., heat stimuli were delivered using the Medoc CHEPS and pressure stimuli were administered via an MRI-Compatible Foot-Sole Stimulator) to systematically evaluate post-stroke changes in pain perception through two experiments. We compared self-reported pain sensitivity, somatosensory thresholds (i.e., warmth and pressure), and pain thresholds (i.e., heat and pressure pain) between ischemic stroke patients and healthy controls in Experiment 1. We focused on pain perception when participants simultaneously experienced heat and pressure in Experiment 2. Results: Experiment 1 showed an absence of a significant correlation between heat and pressure pain thresholds in stroke patients, but this correlation could be observed in healthy controls. Notably, stroke patients had an impairment in pain perception of pressure stimulation at supra-threshold intensities. Experiment 2 observed a similar facilitative pain integration in patients as healthy controls when they perceived heat and pressure stimuli jointly and simultaneously. Conclusions: These findings provide valuable insights into pain perception following a stroke, highlighting the need for tailored evaluation strategies considering the differences in somatosensory modality damage. Full article

Stirling engines are the engines that convert heat energy into mechanical work. This study models a 50 W linear generator designed for integration with a Stirling engine. To develop a model, the base design of the already developed 1 kW model was used, and its size was proportionally reduced to match the stroke of the Stirling engine. By reducing the length of the 1 kW model to a length scale factor (LSF) of 0.5, the stroke level of the engine was determined. However, the radius of the LSF 0.5 linear generator model was adjusted to match the engine. After finalizing the 50 W linear generator dimensions, the model was simulated using MAXWELL v14. software to compute output power and other electrical parameters. This study also analyzed the losses of the 50 W linear generator and its phasor diagram. Later, the output values generated using MAXWELL software were compared with the results obtained using SAGE v11. software for verification. The outcome of this study was a model that achieved an output power of 50 W with an efficiency of 90% and a generator size of 96 mm. Because of its versatility, low weight, and high efficiency, it can be used in a wide range of applications. Due to its small size, it can be utilized for empowering humanoid robots, radioisotope power, space exploration, etc. Full article

Waste heat recovery using Organic Rankine Cycle (ORC) systems shows significant potential for reducing CO₂ emissions from ships. This study designs and analyzes ORC systems for recovering multi-grade waste heat from the exhaust gas, jacket water, and scavenging air of a marine two-stroke diesel engine. A thermodynamic model is developed to investigate the effects of working fluid preheating temperature, evaporation pressure, and heat source conditions on system performance. Results show that appropriately increasing the preheating temperature of the working fluid can enhance power output. For hydrocarbons with higher critical temperatures, power output exhibits an extremum as preheating temperature increases, while for fluids with lower critical temperatures, power output increases continuously until the evaporation pressure limit is reached. Increasing evaporation pressure decreases power output but improves thermal efficiency, with a corresponding increase in heat transfer and exergy loss rates in the exhaust gas preheater. Additionally, the temperature of the heat source has an important effect on the energy and exergy balance distribution and power output of the ORC. For every 10 K rise in exhaust temperature, the bottoming cycle power output of cyclohexane increases by approximately 12.3%. This study provides theoretical support for efficient marine waste heat recovery and working fluid selection. Full article

Moyamoya disease (MMD) is a cerebrovascular condition characterized by progressive stenosis of intracranial arteries, leading to stroke. While MMD was long considered a genetic disorder, emerging evidence suggests autoimmune mechanisms may contribute to its pathogenesis. The role of non-coding RNAs (ncRNAs) in the pathogenesis of MMD is under heated discussion, and a competitive endogenous RNA (ceRNA) network involving MMD-related ncRNAs has not been constructed. In this study, we integrated multiple bioinformatic analyses on transcriptomic data from the middle cerebral arteries of MMD patients and controls. Our analysis revealed a significant enrichment of innate immune system pathways, including antigen processing and macrophage activation, in MMD tissue. We constructed a robust ceRNA network centered on the long non-coding RNA MALAT1, identifying 15 core mRNA targets. A classifier built from these MALAT1-related genes accurately distinguished MMD patients from controls, with an area under the curve of 0.869 in independent validation. Furthermore, immune deconvolution analysis showed a marked increase in microvascular endothelial cells and a decrease in CD4⁺ memory T cells and regulatory T cells in MMD arteries. The expression of the MALAT1 network genes strongly correlated with these shifts in cellular composition, positively with endothelial cells and negatively with T cells. Our findings uncover a MALAT1-driven ceRNA network that links immune dysregulation to vascular changes in MMD, highlighting MALAT1 as a potential biomarker and therapeutic target. Full article

The National Adaptation Plan of Bangladesh identifies eleven climate-stressed zones, placing nearly 100 million people at high risk of climate-related hazards. Vulnerable groups such as the poor, floating populations, daily laborers, and slum dwellers are particularly affected. However, there is a lack of data on climate-sensitive diseases and related hospital visits in these areas. This study explored the prevalence of such diseases using the Delphi method through focus group discussions with 493 healthcare professionals from 153 hospitals in 156 upazilas across 21 districts and ten zones. Participants were selected by district Civil Surgeons. Key climate-sensitive diseases identified included malnutrition, diarrhea, pneumonia, respiratory infections, typhoid, skin diseases, hypertension, cholera, mental health disorders, hepatitis, heat stroke, and dengue. Seasonal surges in hospital visits were noted, influenced by factors like extreme heat, air pollution, floods, water contamination, poor sanitation, salinity, and disease vectors. Some diseases were zone-specific, while others were widespread. Regions with fewer hospital visits often had higher disease burdens, indicating under-reporting or lack of access. The findings highlight the need for area-specific adaptation strategies and updates to the Health National Adaptation Plan. Strengthening resilience through targeted investment and preventive measures is crucial to reducing health risks from climate change. Full article