Temperature Rise Research Articles

Dual lanthanide Complexes-Loaded ratiometric nanothermometer for elucidating intracellular variations of temperature and calcium transport

Herein, we report a ratiometric nanothermometer to study the correlation of heat/temperature and intracellular calcium transport. Firstly, poly(methyl methacrylate)-based copolymeric nanoparticles (NPs) from nanoprecipitation encapsulates two lanthanide complexes (Eu(DNPD)3Phen and Sm(DBM)3Phen) to enhance fluorescence of lanthanide ions (Ln3+). NPs were thereafter coated with an amphiphilic block copolymer pluronic F-127 to prevent nonspecific interaction between NPs and proteins, which ensures internalization of the nanothermometer into living cells. The back energy transfer (BET) from the excited state of Ln3+ to the triplet energy levels of ligand endows the temperature dependence on ratiometric fluorescence of Eu3+ and Sm3+. This nanothermometer has excellent anti-interference ability, ensuring accurate cell temperature measurement within a range of 29.0–40.0℃. It exhibits a maximum relative thermal sensitivity of 1.9 % ℃-1 at 29.0℃ and a minimum temperature resolution of 0.1℃ at 39.0℃ in live HeLa cells. The nanothermometer was applied for studying temperature or heat induced intracellular Ca2+ transport. It illustrated that free cytoplasmic Ca2+ concentration ([Ca2+]i) increased only when the cell temperature reached a certain threshold under photothermal stimulation, and the rise of temperature corresponds to the increase of [Ca2+]i. Furthermore, Ca2+ burst induced Ca2+ transport from cytoplasm to endoplasmic reticulum, which promoted ATP hydrolysis along with the rise of intracellular temperature. 200 s stimulation with FCCP enhanced ca. 1.7℃ of intracellular temperature along with 2.2 folds increment of [Ca2+]i, as FCCP induces Ca2+ efflux from mitochondria by increasing proton concentration therein. These results indicate that a close relationship between intracellular temperature and Ca2+ transport, which is of great significance for further understanding the role of temperature in signaling pathways and neurotransmitter release events.

Comparison of Proxy-Shortwave Cloud Albedo from SBUV Observations with CMIP6 Models

Abstract We construct a long-term record of top of atmosphere (TOA) shortwave (SW) albedo of clouds and aerosols from 340-nm radiances observed by NASA and NOAA satellite instruments from 1980 to 2013. We compare our SW cloud+aerosol albedo with simulated cloud albedo from both AMIP and historical CMIP6 simulations from 47 climate models. While most historical runs did not simulate our observed spatial pattern of the trends in albedo over the Pacific Ocean, four models qualitatively simulate our observed patterns. Those historical models and the AMIP models collectively estimate an equilibrium climate sensitivity (ECS) of ∼3.5°C, with an uncertainty from 2.7° to 5.1°C. Our ECS estimates are sensitive to the instrument calibration, which drives the wide range in ECS uncertainty. We use instrument calibrations that assume a neutral change in reflectivity over the Antarctic ice sheet. Our observations show increasing cloudiness over the eastern equatorial Pacific and off the coast of Peru as well as neutral cloud trends off the coast of Namibia and California. To produce our SW cloud+aerosol albedo, we first retrieve a black-sky cloud albedo (BCA) and empirically correct the sampling bias from diurnal variations. Then, we estimate the broadband proxy albedo using multiple nonlinear regression along with several years of CERES cloud albedo to obtain the regression coefficients. We validate our product against CERES data from the years not used in the regression. Zonal mean trends of our SW cloud+aerosol albedo show reasonable agreement with CERES as well as the Pathfinder Atmospheres–Extended (PATMOS-x) observational dataset. Significance Statement Equilibrium climate sensitivity is a measure of the rise in global temperature over hundreds of years after a doubling of atmospheric CO2 concentration. Current state-of-the-art climate models forecast a wide range of equilibrium climate sensitivities (1.5°–6°C), due mainly to how clouds, aerosols, and sea surface temperatures are simulated within these models. Using data from NASA and NOAA satellite instruments from 1980 to 2013, we first construct a dataset that describes how much sunlight has been reflected by clouds over the 34 years and then we compare this data record to output from 47 climate models. Based on these comparisons, we conclude the best estimate of equilibrium climate sensitivity is about 3.5°C, with an uncertainty range of 2.7°–5.1°C.

Can limiting global temperature rise to below 2°C warming prevent the emergence of unprecedented drought?

In the context of anthropogenic global warming, unprecedented drought is expected to emerge over some regions where drought conditions exceed the variation range of the natural state. However, it is still unclear how the 1.5°C and 2°C warming targets proposed by the Paris Agreement will delay or even prevent the emergence of unprecedented drought. To illustrate the benefits of the two warming targets for mitigating drought conditions, this study investigated the time of emergence (TOE) of unprecedented meteorological drought as indicated by the Standardized Precipitation Evapotranspiration Index (SPEI) using the Coupled Model Intercomparison Project Phase 6 (CMIP6) model ensembles forced by 4 Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). In particular, the pattern of TOE is explored for 4 pseudo warming scenarios under which global mean surface temperature (GMST) increases by 1.5°C, 2°C, 3°C, and 4°C above pre-industrial levels, respectively. The results suggested that: (1) Under the 1.5°C and 2°C warming scenarios, unprecedented meteorological drought is anticipated to emerge over southern Africa, Arabian Peninsula, central Asia, Mongolia, southwestern South America, and western and eastern Australia. (2) Under the 3°C and 4°C warming scenarios, unprecedented meteorological drought will expand to western North America, the Amazon, and the Mediterranean. (3) The comparisons with the exposure under the 3°C and 4°C warming scenarios show that the aspirational 1.5°C and 2°C Paris Agreement warming targets can prevent at least 0.6 × 107 km2 of land area, 1.4 × 108 people, and 0.6 × 106 km2 of cropland area from suffering the emergence of unprecedented meteorological drought.

Are We the Reason for Climate Change?

Abstract: Climate change is a pressing global issue, primarily driven by human activities such as burning fossil fuels, deforestation, and industrial processes, which release greenhouse gases into the atmosphere. This study explores the evidence supporting the human role in climate change, assessing individual carbon footprint patterns and their contribution to greenhouse gas emissions. It discusses various human activities leading to carbon emissions and presents a method for calculating individual carbon footprints. Additionally, it outlines strategies to reduce carbon footprints, including using public transport, minimizing electricity usage, and promoting sustainable practices like recycling and planting trees. This study highlights the urgent need for collective action to address climate change, emphasizing the critical importance of transitioning to sustainable energy sources and adopting mitigation strategies to limit temperature rise.

Effects of essential oils on heat-stressed poultry: A review.

While certain animal species are sensitive to heat stress, poultry particularly modern breeds, are more susceptible to high ambient temperatures. This has major implications for the poultry industry, as heat stress causes large financial losses. These economic losses will probably increase as a consequence of a predicted rise in global temperatures. Heat stress adversely affects various aspects of poultry, including physiological responses, growth and production performance, meat quality, egg quality, and reproductive activities. These effects occur through specific molecular and metabolic pathways. To mitigate the impacts of heat stress, it is crucial to go beyond administrative practices and implement dietary interventions during high ambient temperature. Such interventions aim to optimize the development of stressed bird species in terms of performance, health, and profitability. Essential oils have shown promising in mitigating the negative effects of heat stress and improved antioxidant status, growth and yield performance, as well as meat and egg quality in poultry. They actively participate in certain metabolic and molecular pathways that help to counteract the effects of heat stress. The article discusses the impacts of essential oil supplementation on the relationships between antioxidant enzyme activity, these molecular, and metabolic pathways, as well as various parameters such as growth and yield performance, and product quality heat-stressed poultry.

Waste-Heat Renewable Gasifier Design through Taguchi's Method and MANFIS

Ensuring a global average temperature increase of no more than 1.5°C is crucial for aligning with the objectives of the Paris Agreement. The Intergovernmental Panel on Climate Change (IPCC) estimates that a 45% reduction in carbon dioxide emissions by 2030 or a 25% reduction by the same year is necessary to cap the temperature rise at 2°C. Failure to achieve this target by 2030 would necessitate substantial subsequent reductions to compensate for the delayed progress toward net zero emissions, potentially incurring higher costs. Elevating the focus on enhancing energy efficiency has emerged as a key strategy in expediting progress toward these climate goals. Hydrogen, renowned for its high efficiency and emission-free combustion, is anticipated to play a pivotal role in this endeavor. Traditionally, gasifiers have served as the conduit for transforming inexpensive fuels like coal or biomass into hydrogen. However, their energy-intensive nature poses a challenge.Addressing this inherent issue, an innovative approach known as the external-heating gasifier has been proposed and designed. The design of the external-heating gasifier represents a quintessential nonlinear and multiple-input multiple-output (MIMO) problem. To achieve optimal performance, the integration of Taguchi's method and inverse-model technology has been employed, with a simulation platform developed using the COMSOL Multiphysics software.Initially, Taguchi's method was utilized to determine the minimum number of experiments required for a full-factorial design and identify the most critical factors influencing product performance. Subsequently, an adaptive neuro-fuzzy inference system (ANFIS) was developed with a MIMO–ANFIS architecture. This system was employed to train an inverse model, facilitating the mapping of relationships between each input and output set. In essence, this approach enables the identification of manufacturing parameters that result in optimal performance. To illustrate the efficacy of the proposed method, a simulation study on an existing gasifier is presented.

Assessment of the Potential for Increasing the Energy Efficiency in the Cooling Sector

Cooling supply to ensure the indoor microclimate is becoming more important as global average air temperatures rise. With growing societal demands for higher thermal comfort and increasing individual cooling solutions in the building sector, global energy consumption for cooling is increasing accordingly. Scientific literature and studies estimate that the demand for cooling energy will have a significant impact on global energy demand in the future. In compliance with the European Union goal of achieving climate neutrality by 2050, it is essential to find solutions for reducing energy consumption in the building sector, which is already among the largest energy consumers and greenhouse gas emission producers. Replacing individual cooling solutions with district cooling in urban areas where higher energy density can be reached is one of the solutions for decarbonizing the building sector. To spatially assess the feasibility of district cooling in certain areas, energy demand mapping can be performed. Within this research mapping is carried out using a geographical information system (GIS) tool. The purpose of the mapping is to identify the places in the city of Riga with the highest district cooling potential. Spatial assessment using a GIS tool can be done in different ways – mostly it depends on the available data. The spatial data (buildings) of the cadastral information system and additional detailed information about buildings were obtained from the Latvian open data portal. Information on the type of use of the building, indoor area and the age of building was attached to each building on the map. Then building energy certificate data containing information on specific energy consumption for cooling (kWh/m2 per year) was obtained from the same portal. By processing the data of energy certificates of buildings, excluding outliers, a specific index was obtained for different types of buildings. For the residential sector, the age of the building is also used. Using cadastral data on the indoor area of buildings and the type of building use, the theoretical cooling demand in Riga is calculated and results are quantified and displayed visually. By visualizing the results with the GIS tool, hot spots with the highest cooling energy demand were detected. Results can be further used to calculate the technical and economic justification for the district cooling solutions in specific areas as well as assess the energy efficiency that would be provided by implementation of district cooling solutions.

Prediction of ocean temperature based on ARIMA model

As an important parameter of the Earth's ecosystem, ocean temperature has always been a hot research field for scholars, and the rise in ocean temperature caused by global warming is a topic related to the fate of humanity. The prediction of future ocean temperature is of great significance. The ARIMA model, as a typical prediction model, is highly favored by scholars from various countries due to its accuracy and adaptability. In this paper, the ARIMA multiplication model with seasonal effect is used to forecast the trend of ocean temperature change in the next year, and to prediction graph as well as specific reference values are given. The conclusion is as follows: The global average monthly ocean temperature will continue to rise in the next year. Therefore, this article believes that the government should promptly introduce relevant policies to address the rise in ocean temperature caused by global warming, and people should also fulfill their obligations to protect the environment.

Predicting and probing the local temperature rise around plasmonic core-shell nanoparticles to study thermally activated processes.

Ultrafast spectroscopy can be used to study dynamic processes on femtosecond to nanosecond timescales, but is typically used for photoinduced processes. Several materials can induce ultrafast temperature rises upon absorption of femtosecond laser pulses, in principle allowing to study thermally activated processes, such as (catalytic) reactions, phase transitions, and conformational changes. Gold-silica core-shell nanoparticles are particularly interesting for this, as they can be used in a wide range of media and are chemically inert. Here we computationally model the temporal and spatial temperature profiles of gold nanoparticles with and without silica shell in liquid and gas media. Fast rises in temperature within tens of picoseconds are always observed. This is fast enough to study many of the aforementioned processes. We also validate our results experimentally using a poly(urethane-urea) exhibiting a temperature-dependent hydrogen bonding network, which shows local temperatures above 90 ◦C are reached on this timescale. Moreover, this experimentally shows the hydrogen bond breaking in such polymers occurs within tens of picoseconds.

Study on the active regeneration characteristics of DPF in diesel-methanol dual-fuel engine under different exhaust oxygen concentrations

This study proposes a method to control exhaust oxygen (O2) concentration by adjusting the intake throttle valve, achieving intake throttling, and reducing intake airflow. The impact of exhaust O2 concentration at the inlet of the diesel oxidation catalyst (DOC) the diesel particulate filter (DPF) performance during active regeneration in diesel engines is investigated. Experiments are conducted under methanol substitution rates (MSR) of 0% and 20% to investigate how different exhaust O2 concentrations affect the performance of the DOC and DPF during active regeneration. A comparative analysis of fuel consumption and cumulative CO2 emissions during DPF active regeneration under different exhaust O2 concentrations is performed. Research results indicate that decreasing exhaust O2 concentration reduces exhaust flow, raising DOC inlet temperature. This enhancement improves catalytic conversion efficiency, accelerating the rise in DPF inlet temperature. The average conversion efficiency of DOC to unburned methanol exceeds 98.07%. After initiating DPF active regeneration, O2 concentration sharply drops, leading to elevated CO2 emissions. As soot combustion advances, the required O2 diminishes, resulting in a gradual rise and eventual stabilization of O2 emissions. Economically and environmentally, irrespective of MSR (20% or 0%), there exists an optimal exhaust O2 concentration that minimizes effective regeneration time during DPF active regeneration, achieving minimal fuel consumption and the lowest CO2 mass emissions. This study offers theoretical support for optimizing energy-saving and emission-reduction processes during DPF active regeneration.

Understanding the Influences of Multiscale Waviness on the Elastohydrodynamic Lubrication Performance, Part II: The Partial-Film Condition

This paper is the second part of a two-part report studying the responses of a typical point-contact elastohydrodynamic lubrication (EHL) system to multiscale roughness mimicked by wavy surfaces. The wavy surfaces are defined by three key parameters: amplitudes, frequencies, and directions. The previous Part I paper focuses on the full film lubrication condition, while the current paper focuses on the partial film regime where asperity contacts occur. A transient thermal EHL model simulates lubrication problems with different waviness parameters, loads, and speeds. The total number of simulations is 1600. Performance parameters, including the asperity contact ratio, minimum film thickness, maximum pressure, central point film thickness, central point pressure, mean film thickness, coefficient of friction (COF), and the maximum temperature rise, are obtained for each simulation. These performance parameters are post-processed in the same manner as those in the previous Part I paper. The influences of the waviness parameters, load, and speed values on the eight performance parameters are discussed.

Thermodynamic and kinetic study on the catalysis of tributyl aconitate by Amberlyst-15 in a cyclic fixed-bed reactor

Abstract Tributyl aconitate is a new type of alternative plasticizer to phthalates. Amberlyst-15 was used to catalyze the esterification of aconitic acid and n-butanol for the preparation of tributyl aconitate in a cyclic fixed-bed reactor. The influence of the reaction conditions on the conversion was investigated. The results showed that the conversion of aconitic acid increased significantly with the rise of temperature and catalyst loading. The reaction conditions were optimized as: temperature: 115 °C; initial mass ratio of AA and n-butanol: 1:4; catalyst loading: 25 %; reaction absolute pressure: 85 kPa; volume flow rate: 30 mL min−1. Thermodynamics and kinetics of the reaction was studied. The non-ideality of the reaction system was rectified using the UNIFAC group contribution method. The kinetic process was simulated using the pseudo-homogeneous (PH) model, Eley-Rideal (E-R) model, and Langmuir-Hinshelwood-Hougen-Watson (LHHW) model. The results revealed that the E-R model exhibited superior suitability in simulating the kinetic process.

Impact of air supply cessation time on thermal characteristics in coal mine dead-end roadway fires: An experimental study

Following a fire incident in a coal mine dead-end roadway, shutting down the local ventilator can influence fire progression. This study delves into the impact of local ventilator shutdown time (i.e. air supply cessation time) on fire source combustion dynamics through small-scale experiments. Results indicate that the sudden cessation of air supply will prompt ghosting flame and even fire self-extinguishing. The ghosting flame emerges due to the uneven distribution of fuel vapor and oxygen concentrations, its moving direction is related to ventilation conditions and fire source combustion mode. And the burning time of the fire source after air supply cessation diminishes with increasing air supply cessation time and pool size but increases with higher ventilation velocities. Additionally, sudden cessation of air supply decreases smoke oxygen content and significantly elevates CO levels, particularly impacting ventilation-controlled fires. Moreover, this interruption leads to a substantial rise in smoke temperature, heightening fire risk. Thus, prudent closure of the local ventilator in dead-end roadway fires is recommended, particularly in scenarios of inadequate ventilation and prolonged combustion. These findings offer fresh insights into dead-end roadway fire behavior and furnish valuable guidance for firefighting and rescue operations in similar structures.

Optimizing pressure gradient on the MHD peristaltic blood flow of nanofluids by - response surface methodology

This study focuses on optimization of pressure gradient on MHD peristaltic nanofluid flow by response surface methodology (RSM). The governing equations, including continuity, motion, nanoparticle, and concentration force are solved by disregarding inertial forces and employing the approximation of long-wavelength. The perturbation method is used to solve the resultant nonlinear coupled partial differential equation analytically. Mathematical and graphical outputs for concentration, temperature, and pressure rise, considering all physical parameters, are presented. Numerical computation is applied to assess expressions for friction forces and pressure rise. Magnetohydrodynamics has various applications in various microchannel designs for efficacious flow control in pumping fluids for both pulsating and non-pulsating continuous flow. Finally, Response Surface Methodology (RSM) is used for performing sensitivity analysis and its optimization. ANOVA tables are generated with the help of MINITAB-19 which is a statistical software. The sensitivity results are displayed in tabular and graphical form and concluded that M is more sensitive than other input parameters for ΔPat the low level and the input parameter Nt is most sensitive among others at middle and high levels. Further, Temperature and pressure of the flow has different responses for various values of magnetic, thermophoresis and Brownian motion parameter.

Interacting impacts of hydrological changes and air temperature warming on lake temperatures highlight the potential for adaptive management.

Globally, climate warming is increasing air temperatures and changing river flows, but few studies have explicitly considered the consequences for lake temperatures of these dual effects, or the potential to manage lake inflows to mitigate climate warming impacts. Using a one-dimensional model, we tested the sensitivity of lake temperatures to the separate and interacting effects of changes in air temperature and inflow on a small, short-residence time (annual average ≈ 20days), temperate lake. Reducing inflow by 70% increased summer lake surface temperatures 1.0-1.2°C and water column stability by 11-19%, equivalent to the effect of 1.2°C air temperature warming. Conversely, similar increases in inflow could result in lake summer cooling, sufficient to mitigate 0.75°C air temperature rise, increasing to more than 1.1°C if inflow temperature does not rise. We discuss how altering lake inflow volume and temperature could be added to the suite of adaptation measures for lakes.

Characteristics of Insulating Panels Realised from Coconut Palm Fibres for Low-Temperature Thermal Insulation

In recent years, there has been growing interest in issues relating to pollution and energy consumption, and the resulting regulations have led the construction sector to focus on thermal insulation. The application of bio-based insulation materials can help to minimise the environmental impact of buildings by reducing energy demand both during construction and over the lifetime of the building. Agroforestry biomass plays an interesting role, as its use can reduce greenhouse gas emissions. The aim of this work is to produce insulating panels from agroforestry by-products for low-temperature thermal insulation applications. The insulating panels in this study are produced from coconut palm fibres and their thermophysical properties are determined. They were produced using a human-motricity press and the temperature rise was controlled using the hot-tape method. Characteristics such as calorific value and modelling of temperature rise as a function of time to calculate thermal conductivity, thermal effusivity and diffusivity were determined. The calorific value varies from 3668.0 to 4135.0 and from 3742.0 to 4186.0 cal.g-1 when the moisture content is 11.28 and 10.61%, respectively. The thermal conductivity, effusivity and thermal diffusivity are 0.4 W.m-1.K-1, 760.30 J.m-2.°C-1.s-1/2 and 2.73.10-7 m.s-1, respectively. In view of these results, coconut fibre represents a potential precursor to produce insulating panels.

Safety and efficacy of very high-power short ablation in superior vena cava isolation in patients with atrial fibrillation

Abstract Backgrounds The superior vena cava (SVC) plays an important role in non-pulmonary vein (PV) foci to trigger atrial fibrillation (AF) and thus are occasionally isolated. A major complication in SVC isolation is phrenic nerve injury, and a shallower ablation depth might be less likely to cause complications. Recently, very high power short ablation (vHPSD) has been demonstrated to be effective in PV isolation. On the other hand, vHPSD has been reported to have shallower depth than the low-power ablation strategies, suggesting concerns about insufficient ablation in thicker myocardial sites. The vHPSD might be effective and safe in SVC isolation thinner than myocardium, however, the details were not elucidated. Purpose This study was aimed to examine the safety and efficacy of vHPSD strategy in SVC isolation, compared retrospectively with low power ablation strategies. Methods Patients with AF who were undergoing first-time SVC isolation were included. An activation map was performed from the SVC to the right atrium during sinus rhythm, and a circumferential isolation line was designed by the CARTO system at a height of 1.5cm above the earliest site. The site and extent of capture of the phrenic nerve by pacing on the circumferentially designed ablation line were recorded. The first step was to perform circumferential ablation except for the sites where the phrenic nerve was captured. If the SVC isolation was completed, the procedure was completed. If the isolation was inadequate, the sites of capture of the phrenic nerve were also ablated. Two groups of patients were analyzed: those performing vHPSD (n=27, vHPSD group) with a power of 90 watts for 3 seconds or those using lower-power (n=20, LP group) limited to 20-40 watts. Results Forty-seven patients who underwent the initial SVC isolation were evaluated. We analyzed all 351 points in the vHPSD group and all 364 points in the LP group with ablation of SVC. No differences were found in the distance of the SVC circumference on the isolation line (vHPSD: 71±10 vs. LPLD: 71±11mm, p=0.95) or the extent of phrenic nerve capture (12±7 vs. 12±9mm, p=0.82). All patients in the vHPSD group were successfully isolated first-pass; the first-pass isolation rate tended to be higher than in the LP group (100% vs. 85%, p=0.07). Differences were observed in temperature rise (49±4 vs. 28±4 degrees, p<0.001) and impedance drop (12±4 vs. 7±5Ω, p<0.001), although there were no differences in the contact force (15±8 vs. 15±7g, p= 0.73). The vHPSD group achieved SVC isolation with a shorter procedure time (9±4 vs. 17±5 min, p<0.001) and fewer ablation points (13±4 vs. 18±4, p<0.001) compared to the LP group. In the vHPSD cases, ATP was administered after isolation, but no dormant conduction was observed. Only in one case in the LP group, transient phrenic nerve injury was observed. Conclusion The vHPSD for SVC isolation might be safe and result in shorter procedure time and fewer ablation points.

Transparent radiative cooling cover window for flexible and foldable electronic displays

Transparent radiative cooling holds the promise to efficiently manage thermal conditions in various electronic devices without additional energy consumption. Radiative cooling cover windows designed for foldable and flexible displays could enhance cooling capacities in the ubiquitous deployment of flexible electronics in outdoor environments. However, previous demonstrations have not met the optical, mechanical, and moisture-impermeable criteria for such cover windows. Herein, we report transparent radiative cooling metamaterials with a thickness of 50 microns as a cover window of foldable and flexible displays by rational design and synthesis of embedding optically-modulating microstructures in clear polyimide. The resulting outcome not only includes excellent light emission in the atmospheric window under the secured optical transparency but also provides enhanced mechanical and moisture-impermeable properties to surpass the demands of target applications. Our metamaterials not only substantially mitigate the temperature rise in heat-generating devices exposed to solar irradiance but also enhance the thermal management of devices in dark conditions. The light output performance of light-emitting diodes in displays on which the metamaterials are deployed is greatly enhanced by suppressing the performance deterioration associated with thermalization.

Reduction in the Constrained Shrinkage and Crack Risk of Different-Strength-Level Concretes with Saturated Ceramsite

To reduce the shrinkage and cracking risk of concrete, internal curing technology was applied to modify concretes with different strength levels (C30 and C60) by incorporating saturated ceramsite. Three kinds of tests were carried out to study the effects of the incorporation of saturated ceramsite on the compressive strength, hydration temperature rise, and shrinkage behavior of the concretes, respectively. It was found that the internal hydration temperature rise of the concrete could be delayed and reduced due to the internal curing effect of ceramsite. Moreover, both the early-stage and long-term constrained shrinkage behavior of the internal cured concretes were monitored with embedded strain sensors and compared with free shrinkage behavior. For the C30 concrete system, with the incorporation of saturated ceramsite, its constrained shrinkage at 96 h was reduced greatly from 181 µε to 36 µε. Furthermore, the surface-attached-sensor method was also used to study the shrinkage behavior of the concrete beams and it was found that the sensor location affected the measured shrinkage values greatly. The model beams of both the C30 and C60 concrete systems shrunk significantly in the first month, and the highest cracking risk occurred in this period as well. The internal curing effect of saturated ceramite could significantly reduce the constrained shrinkage of the concrete beam, evidently diminishing the cracking risk. More importantly, compared to the ordinary concrete C30 system, it was revealed that such an internal curing effect was more effective in promoting the performance of the higher-strength concrete (C60). With this effect, the cracking risk of C60 concrete was reduced from 0.69 to 0.37 at 300 days and changed little from then on.

Design and Optimization of Heat Dissipation for a High-Voltage Control Box in Energy Storage Systems

Abstract To address the issue of excessive temperature rises within the field of electronic device cooling, this study adopts a multi-parameter optimization method. The primary objective is to explore and realize the design optimization of the shell structure of the high-voltage control box, aiming to effectively mitigate the temperature rise in internal components and enhance their thermal management efficacy without altering the fan performance, environmental conditions, or spatial layout. Initially, the study employs computational fluid dynamics methods to investigate the heat dissipation characteristics of the high-voltage control box, subsequently verifying the simulation parameters' accuracy through temperature rise tests. Building upon this foundation, the article conducts a thorough analysis of how the position and shape of the box's openings impact the device's temperature rise. The findings suggest that configuring circular openings on the front and rear sides can optimize the heat dissipation effect. Moreover, the SHERPA algorithm was employed to refine the size and distribution of the openings on the outer shell of the high-voltage control box through multi-parameter optimization, yielding locally optimal structural parameters. Post-optimization, the temperature measurement points within the high-voltage control box exhibited a maximum reduction in temperature rise of 27.16%. The pivotal contribution of this methodology is the application of a data-driven decision-making process for the enhancement of conventional heat dissipation designs. This research offers invaluable practical insights and novel perspectives on the optimization of thermal management designs for box-type electronic devices, significantly advancing the field of thermal management technology in electronic devices.