Drop In Surface Temperature Research Articles

Effect of a tropical cyclone on the pelagic ecosystem of a continental shelf

AbstractThis study aimed to comprehend the effects of Typhoon Maria on the pelagic ecosystem in the southern East China Sea. Shipboard measurements were conducted at eight sampling stations before (2–4 d) and after (3–6 d) the typhoon, which enabled the evaluation of the potential impacts of the typhoon on this pelagic ecosystem, with particular focus on carbon dynamics. Following the typhoon's passage, there was a slight drop in sea surface temperature. The response of the variables to the typhoon, however, exhibited variations at different sampling stations. For further analysis, t‐tests compared variables, while type II regression assessed the linear correlation between two variables. Overall, during the post‐typhoon period, concentrations of nitrate, chlorophyll a, primary production, bacterial biomass and production, plankton community respiration, and abundance of large phytoplankton (> 2 μm) and the relative abundance of picophytoplankton among larger‐sized picoeukaryotes were higher compared to the pre‐typhoon period. The mean value of fugacity of CO2 was similar to or slightly lower than pre‐typhoon period. Although the typhoon‐induced vigorous primary production might have absorbed a significant amount of CO2, the decrease in fugacity of CO2 could have been offset by the plankton community respiration. The findings suggest that the typhoon enhanced physical disturbance and increased water column mixing, which, in turn, augmented nutrient availability and promoted plankton growth in the shallow water column. Overall, this study sheds light on the complex interactions between typhoons and marine ecosystems and highlights the importance of further investigating these phenomena to better understand their ecological implications.

LC3 cementitious binder incorporating microencapsulated phase change materials for self-defrosting traffic surfaces

Exposed surfaces of bridge decks, viaducts and pavements incur ice formation and accumulation of snow in cold seasons, which threatens traffic safety. Mitigating this problem using traditional methods such as deicing salts have caused ecosystem damage and inflicted substantial reinforcement corrosion and surface scaling to bridge decks and pavements, thus compromising their service life and causing colossal economic loss. This paper presents an alternative solution to overcome this problem through the development of a sustainable LC3 cementitious material incorporating micro-encapsulated phase change material (MEPCM) with low phase transition temperature to delay the surface temperature drop and mitigate snow accumulation and ice formation. MEPCM was incorporated in the cementitious matrix at 0 %, 10 % and 20 % by binder mass. Paste and mortar mixtures were prepared to investigate the microstructural, mechanical, physical, and thermal properties. Test results showed that incorporating MEPCM in the LC3 matrix achieved adequate compressive strength. Thermal simulations and visual observations conducted on mortar samples in the laboratory and outdoor exposure showed that MEPCM can effectively regulate the surface temperature of the LC3 matrix and mitigate temperature drops as well as snow accumulation. Analysis of temperature data in the 2023–2024 winter season of Hamilton, Ontario, Canada indicated that the MEPCM incorporated in mortar samples could effectively regulate 40 % of the total days considered and mitigate surface ice formation and snow accumulation, which provides both economic and environmental benefits.

Monitoring changes in hydric properties of treated stone material with conservation products by time-sequential IR thermography

A methodological approach for a semi-quantitative non-destructive testing (NDT) of the effects on hydric properties after the application of different conservation treatments (commercial ethylsilicate and siloxane compounds with consolidant, water repellent or consolidant + water repellent properties) is presented in this study. The NDT used for this purpose is a simplified method of time-sequential infrared thermography (IRT) on stone (granite and marble, treated and untreated) from the Roman theatre of Merida (Spain), which was listed by UNESCO as World Heritage Site in 1993.As water evaporation modifies temperature intensely, IRT enables monitoring the response of the stone samples during water absorption-evaporation processes. The comparative analysis between treated and non-treated specimens was performed by calculating the rate of surface apparent temperature change (ΔoC/h) value. The capillary rising test, monitored by IRT, clearly showed a different response of the samples treated with water-repellent treatments, proving their efficiency. Samples treated with organosilicic compounds showed a large and rapid drop in apparent surface temperature, indicating that water accesses rapidly.Results from the evaporation test also show this difference. The surface apparent temperature increased immediately in samples with water-repellent treatments, in which water does not enter inside stone, but remains on the surface. Samples with ethyl silicate, again, show a greater difference with respect to untreated samples, taking longer to recover surface apparent temperature, because the water is retained inside the stone for longer.This study proved simplified time-sequential IRT as a reliable technique for assessing the efficacy of conservation treatments applied to stone materials in laboratory.

Typhoon-Induced Extreme Sea Surface Temperature Drops in the Western North Pacific and the Impact of Extra Cooling Due to Precipitation

Sea surface temperature (SST) responses have been perceived as crucial to consequential tropical cyclone (TC) intensity development. In addition to regular cooling responses, a few TCs could cause extreme SST drops (ESSTDs) (e.g., SST drops more than 6 °C) during their passage. Given the extreme temperature differences and the consequentially marked air–sea flux modulations, ESSTDs are intuitively supposed to play a serious role in modifying TC intensities. Nevertheless, the relationship between ESSTDs and consequential storm intensity changes remains unclear. In this study, satellite-observed microwave SST drops and the International Best Track Archive for Climate Stewardship TC data from 2001 to 2021 were used to elucidate the relationship between ESSTDs and the consequential TC intensity changes in the Western North Pacific typhoon season (July–October). Subsequently, the distributed characteristics of ESSTDs were systematically examined based on statistical analyses. Among them, Typhoon Kilo (2015) triggered an unexpected ESSTD behind its passage, according to existing theories. Numerical experiments based on the Regional Ocean Modeling System were carried out to explore the possible mechanisms that resulted in the ESSTD due to Kilo. The results indicate that heavy rainfall leads to additional SST cooling through the enhanced sensible heat flux leaving the surface layer in addition to the cooling from momentum-driven vertical mixing. This process enhanced the sensible heat flux leaving the sea surface since the temperature of the raindrops could be much colder than the SST in the tropical ocean, specifically under heavy rainfall and relatively less momentum entering the upper ocean during Kilo.

Paleoceanographic importance of tri- and di-unsaturated alkenones through the early phase of Cretaceous Oceanic Anoxic Event 2 from southern high latitudes of the proto-Indian Ocean

Alkenones are biomarkers derived exclusively from species of haptophyte algae. The relative abundance of di- to tri-unsaturated C37 alkenones expressed as UK'37 is widely applied as a sea surface paleotemperature proxy for Cenozoic marine sediments. However, the absence of alkatrienones prior to the Eocene has precluded application of the UK'37 proxy for assessment of Cretaceous paleoclimates. Herein, we report a C40 alkatrienone (tetraconta-9E, 16E, 23E-trien-3-one; C40:3 Et) in deep-sea sediments from southern high latitudes (International Ocean Discovery Program: IODP site U1516). This discovery extends the geologic record of alkatrienones to the late Cenomanian, ∼70 million years earlier than previous reports. The parallel occurrence of higher abundances of a C40 alkadienone (tetraconta-16E, 23E-dien-3-one; C40:2 Et) allowed calculation of the UK’40 unsaturation index, comparable to UK’37. Stratigraphic variations in the δ13C of C40:2 Et revealed an elevated (∼1.5 ‰) positive carbon isotope excursion (CIE) relative to those observed in carbonate from other OAE2 sequences likely reflecting a decrease in global pCO2. The UK’40 profile suggests a concurrent drop in sea surface temperature associated with the decline in pCO2 during the early phase of OAE2. The timing of these environmental perturbations in the southern high latitude of the proto-Indian Ocean suggests they were triggered by volcanism associated with large igneous province (LIP) formation.

Developing computational methods of heat flow using bioheat equation enhancing skin thermal modeling efficiency

PurposeThe main objective of this paper is to investigate the response of human skin to an intense temperature drop at the surface. In addition, this paper aims to evaluate the efficiency of finite difference and finite volume methods in solving the highly nonlinear form of Pennes’ bioheat equation.Design/methodology/approachOne-dimensional linear and nonlinear forms of Pennes’ bioheat equation with uniform grids were used to study the behavior of human skin. The specific heat capacity, thermal conductivity and blood perfusion rate were assumed to be linear functions of temperature. The nonlinear form of the bioheat equation was solved using the Newton linearization method for the finite difference method and the Picard linearization method for the finite volume method. The algorithms were validated by comparing the results from both methods.FindingsThe study demonstrated the capacity of both finite difference and finite volume methods to solve the one-dimensional and highly nonlinear form of the bioheat equation. The investigation of human skin’s thermal behavior indicated that thermal conductivity and blood perfusion rate are the most effective properties in mitigating a surface temperature drop, while specific heat capacity has a lesser impact and can be considered constant.Originality/valueThis paper modeled the transient heat distribution within human skin in a one-dimensional manner, using temperate-dependent physical properties. The nonlinear equation was solved with two numerical methods to ensure the validity of the results, despite the complexity of the formulation. The findings of this study can help in understanding the behavior of human skin under extreme temperature conditions, which can be beneficial in various fields, including medical and engineering.

Theoretical and experimental study of heat and mass transfer, evaporation and ignition drops of monoatomic ethanol/butanol binary mixture in cold air

The study evaporation process results of lower alcohols' single drops (ethanol, butanol and their binary mixtures) with an initial droplet size of 1.5-2.5 mm in air at room temperature and atmospheric pressure are presented. To describe the heat and mass transfer of the fuel mixture's drops with different initial composition, prognostic evaluation of dynamics' changes fuels drops size, composition and temperature during their evaporation are proposed. Taking into account the temperature dependence of the heat of vaporization, an analytical dependence for evaluating the drop surface temperature of one-component evaporating fuels is proposed. Comparative analysis of the calculated model's data allowed to suggest a possible evaporation mechanism of multi-component fuel mixtures droplets and to explain some peculiarities in the behavior of the main characteristics this process. It is shown that the thermocouple wires qualitatively affects the behavior with time of temperature and droplet size. Formula for the drop's temperature during evaporation into account the influence of thermocouple are presented.

Utility of Thermographic Imaging for Callus Identification in Wound and Foot Care

Calluses are thickened skin areas that develop due to repeated friction, pressure, or other types of irritation. While calluses are usually harmless and formed as a protective surface, they can lead to skin ulceration or infection if left untreated. As calluses are often not clearly visible to the patients, and some areas of dead skin can be missed during debridement, accessory tools can be useful in assessment and follow-up. The practical question addressed in this article is whether or not thermal imaging adds value to callus assessment. We have performed a theoretical analysis of the feasibility of thermographic imaging for callus identification. Our analytical calculations show that the temperature drop in the epidermis should be on the order of 0.1 °C for the normal epidermis in hairy skin, 0.9 °C for glabrous skin, and 1.5–2 °C or higher in calluses. We have validated our predictions on gelatin phantoms and demonstrated the feasibility of thermographic imaging for callus identification in two clinical case series. Our experimental results are in agreement with theoretical predictions and support the notion that local skin temperature variations can indicate epidermis thickness variations, which can be used for callus identification. In particular, a surface temperature drop on the order of 0.5 °C or more can be indicative of callus presence, particularly in callus-prone areas. In addition, our analytical calculations and phantom experiments show the importance of ambient temperature measurements during thermographic assessments.

Cyclic Appearance and Disappearance of Aerosol Nucleation in the Boundary Layer of Drops of Volatile Liquid

The cyclic appearance and disappearance of nucleation was observed in the boundary layer of drops of 1,3-propanediol, 1,2-propanediol, and glycerol, close to the boiling point and exposed to a cooler airflow. Although continuous nucleation has previously been widely observed, the cyclic nature of the phenomenon observed here is unusual. It was observed in experiments with free-falling drops and fixed drops in an upflow of air. To investigate this unexpected phenomenon further, the phenomenon was reproduced in two finite volume models. The first model used 1D potential flow solutions to approximate the airflow around the spherical windward face of the droplet. The second model used CFD to model the airflow. Both models used classical nucleation theory, the Stefan–Fuchs model of droplet growth by condensation, mass transfer by evaporation, diffusion, convection, and heat transfer by diffusion and convection. Despite several simplifications, the most important being the assumption that the drop has a uniform temperature, both models predict the frequency of nucleation to be better than the order of magnitude. These models also predict the experimentally observed power law dependence of nucleation frequency on air speed. It is proposed that the cyclic nature of the phenomenon is caused by the following process: the depletion of condensable vapour around the freshly nucleated aerosol due to condensation onto the aerosol results in reduced supersaturation, which stops further nucleation, and then the replenishment of this vapour by diffusion and convection from the parent drop, with nucleation of aerosol recommencing when the supersaturation has recovered sufficiently—then, the repetition of these steps in a cycle. It is proposed that the process depends mostly on the maximum saturation ratio in the boundary layer, which itself is determined by four key dimensionless numbers: the Lewis number, the Peclet number, the Reynolds number, and the ratio of the vapour pressure of the condensable compound at drop surface temperature to the vapour pressure of the same species at ambient temperature. A practical application of the phenomenon may be as a means of validation of thermo-fluid models, which include nucleation.

Thermal-hydraulic characterization of manifold microchannel heat sink with diverging channels and uniform heating

This study presents the design and experimentation of a manifold microchannel heat sink with diverging channels, employing ammonia as the working fluid to evaluate its thermal–hydraulic performance under uniform heating conditions. The impact of heat flux, inlet subcooling, saturation temperature, and outlet thermodynamic quality were investigated. Under single-phase conditions, the heat sink exhibited low sensitivity to variations in heat flux with constant thermal resistance and pressure drop. However, with the onset of boiling, the heat transfer capability and pressure drop rapidly increased. A lower inlet subcooling boosted boiling inside the heat sink, leading to decreased thermal resistance and increased pressure drop. Under near-saturated inlet conditions, a higher saturation temperature enhanced heat transfer owing to smaller bubble nucleation and detachment size. The outlet thermodynamic quality for engineering applications should be moderately low because it provides a balance between high heat transfer capability and low pressure drop. Moreover, the results demonstrated excellent thermal–hydraulic performance, with a heat flux of up to 636.9 W/cm2 efficiently dissipated under uniform heating conditions while maintaining the heating surface temperature and pressure drop below 79.3 °C and 150.3 kPa, respectively.

Eocene paleoceanographic and paleoclimatic events recognized by assemblages of dinoflagellate cysts in the Southwest Atlantic Ocean

Variations in the relative frequencies between cosmopolitan dinoflagellate cysts and Antarctic assemblage species indicate temperature changes and variations of ocean currents during the Paleogene. This study is based on the analysis of 23 samples from two stratigraphic intervals from the Well BP-01 (Imbé Formation), drilled by in the Pelotas Basin offshore. We identified 66 dinoflagellate cyst taxa, 47 of them belong to the Order Gonyaulacales and 19 to the Order Peridiniales. The relative abundance data highlight two different dinoflagellate ecogroups represented by Apectodinium and Enneadocysta in the intervals A and B, respectively. The level with the highest percentages of Apectodinium recorded in the Calcareous Nannofossil Zone N-410 (Ypresian), suggest that the Apectodinium maximum represents the Early Eocene Maximum Thermal Event (EMT-2). Enneadocysta Acmes registered near the Bartonian/Priabonian boundary, can be correlated with a drop in sea surface temperature that occurred after the Mid-Eocene Climatic Optimum. Dinoflagellate occurrences suggest deposition in open sea conditions during the transgressive phase. The P/G ratio does not reach significant values in the analyzed intervals, indicating low dissolved nutrient concentrations.

Experimental and numerical investigations on the effect of a novel internal surface micro-grooving toward improving convective heat transfer performance of tube heat exchangers

In the present work, the use of passive heat transfer enhancement technique through surface alteration was explored. The enhancement was achieved through internal conduit surface micro-grooving using a new apparatus that was developed by modifying a magnetic abrasive finishing technique. A new surface profile was created and later verified using optical and laser profiler measurements. The new profile was numerically investigated to compare the heat transfer and hydrodynamic performance against other profiles that have been studied in the literature. It was found from the results that the new profile shows much higher heat transfer improvement and comparable pressure loss to the previously investigated profiles (i.e., square, rectangular, trapezoidal, and circular). Overall, the new groove geometry provides the highest performance followed by the circular, triangular, curvy, square, and rectangular grooves. Also, the results indicate that designs with a smooth profile performs better than those with sharp edges, owing to the elimination of stationary fluid spots within the grooves. The effectiveness between the profiles was compared based on the level of heat transfer enhancement against the flow penalty. Experimental validation was further conducted for the experimentally generated groove. The results revealed that a relatively small surface temperature drop was obtained, corresponding to a slight improvement in heat transfer. This confirms the results generated by the simulation that groove size plays a major role in attaining significant improvement in heat transfer.

Experimental and parametric analysis of exhaust heat exchanger used in thermoelectric generator

A thermoelectric generator system consists of an exhaust heat exchanger, a thermoelectric module, and water heat exchanger. Perfect heat exchangers recover as much heat energy as possible from engine exhaust with an acceptable pressure drop. The capacity and efficiency of the heat exchanger depend on its shape, type, and material of the heat exchanger. The main objective of this research was to perform a parametric analysis of the test section of the exhaust heat exchanger by using simulation tools. The simulation results were validated with the experimental results to ensure the performance of the simulation model. The performance of the test section was measured in relation to geometry, pressure drop, temperature distribution, fluid velocity, and temperature uniformity coefficient. The test section of 60 mm × 60 mm × 180 mm (F-type) shows a higher surface temperature with an allowable pressure drop than the other types of test section without inserts. The inserts played a vital role in enhancing the surface temperature distribution and uniformity coefficient. The cone type (G-type), cone-cylinder type (H-type), and cone-cylinder-cone type (I-type) inserts were used to improve the performance of the F-type test section. The G-type and H-type test sections of the exhaust heat exchanger have a high surface temperature, high-temperature uniformity, and allowable pressure drop.

Optimization of bifurcating channel cooling system for double inclined conductive panel system under inclined magnetic field

A novel cooling system with wavy branching channels is proposed considering nano-enhanced magnetic field effects for thermal management of double inclined conductive panels. Thermal performance assessment is conducted by varying Reynolds number (250≤Re≤1000), Hartmann number (0≤Ha≤400), magnetic field inclination (250≤γ≤1000), amplitude (0≤Af≤0.4) and wave number (1≤Nf≤12). As the cooling fluid, water with Ag–MgO hybrid nanoparticles is considered. Temperature drops of 4.5 °C and 2.6 °C are obtained with the highest Re for left inclined panel (p1) and right inclined panel (p2). As the vortex distribution is highly affected for the wavy branching channels by the magnetic field strength, its impact on the cooling performance for p1 and p2 are different. It shows a favorable impact for panel p2 while average Nusselt number (Nu) increments become 10% and 6.3% when using flat and wavy branching channels at the highest magnetic field strength. For panel p1, varying inclination of magnetic field results in average surface temperature drop of 1.6 °C for wavy channel. The optimum value of wave number in the corrugated branching channel is Nf=2 for achieving the highest cooling performance while higher amplitudes of corrugation has favorable impacts on the cooling for each of the panels. As compared to un-cooled panel configuration, utilization of flat branching channel with nano-enhanced magnetic field results in 47.4 °C and 48.9 °C surface temperature drops for panels p1 and p2. Optimization based on COBYLA is utilized to achieve additional temperature drops as compared to parametric computational fluid dynamics. The optimum values of (Ha, γ, Af) are obtained as (40, 89, 0.04) at Re=100 and (40, 60.8, 0.0038) at Re=1000. The proposed single cooling method with wavy branching channel under nano-enhanced magnetic field can be used and further developed for effectively cooling of photo-voltaics with inclined arrangement, electronic cooling and many other heat transfer devices.

ПРІОРИТЕТИ У ВИКОРИСТАННІ ВИКОПНИХ ВИДІВ ПАЛИВА ТА УТРИМАННІ ЖИТЛОВОГО ФОНДУ

The trends of global temperature increase in the world due to excessive burning of fossil hydrocarbons are given. Excessive extraction and burning of fossil fuels (hard coal, petroleum products, natural gas) have led to an increase in their cost and climate change. About 40% of CO2 emissions today come from burning coal, 33% from oil refining products, and 22% from natural gas. An increase in CO2 content in the atmosphere leads to a drop in the Earth's surface temperature. At the global level, the world community has adopted three main international agreements on climate change: the UN Framework Convention on Climate Change (1992); Kyoto Protocol (1997); Paris Agreement (2015). More than 190 countries have signed the Paris Agreement. Its main goals are to achieve carbon neutrality by 2050 and to keep the increase in the global average temperature below 2°C by 2100, preferably to 1.5°C.
 The construction industry is responsible for consumption of up to 40% of all energy. which are used in economies countries of the world In the summarized reports of experts at the 27th UN Conference on Climate Change (COP27), which took place in 2022 year in Egypt (Sharm el-Sheikh) it was stated that in 2022 1% more CO2 will be released into the atmosphere than in in 2021. The main volumes of greenhouse gas emissions come from the burning of fossil fuels. Brought comparative analysis of CO2 emissions when burning different types of fuel.
 The dynamics of the production of fossil fuels - hard coal, oil and natural gas - is studied, which indicates a significant decrease in their production and consumption. Modern approaches to the growth of RES volumes are considered, the dynamics of the growth of SPP capacities are given. On the basis of European experience, the prospects for the installation of balcony mini SPPs are shown.
 Individual heating systems and decentralization of engineering systems for providing housing help to increase their stability in adverse conditions. The organizational features of the transfer of the housing stock from a centralized heating system to individual electric and gas heating are revealed. Based on the analysis of the European experience of maintaining the housing stock, the main directions for reducing energy consumption and greenhouse gas emissions of the existing housing stock are given.

Wound pH and Surface Temperature as a Predictive Biomarker of Healing in Diabetic Foot Ulcers.

To monitor wound pH and surface temperature as predictors of wound healing in diabetic foot ulcers (DFU). Prospective, observational, time-bound study of 18 months, enrolling patients aged 18 to 60 years with uninfected DFU. The wound was assessed at baseline and after that, every week for 4 weeks according to the leg ulcer measurement tool (LUMT). Concurrently, wound surface pH and temperature were measured. The data were analyzed using descriptive statistics, and a P-value < .05 was considered statistically significant. Fifty-four patients with DFU were included in the study with a mean age of 55 years and a male to female ratio of 1.57. The wound showed progressive improvement, a maximum mean LUMT score of 48.89 (± 2.81) at the initial evaluation and decreased progressively to the mean of 19.80 at week 4 (± 3.43), both of which were statistically significant (P-value < .001). Similarly, the median wound pH progressively reduced from 7.7 at baseline to 7.20 in the fourth week, and median wound temperature decreased from 90°F (32.22 °C) at baseline to 85°F (29.44 °C) in the fourth week, both of which were statistically significant (P-value < .001). Progressive and significant change in wound pH to acidic and drop in wound surface temperature, both corresponding to improvement in the status of DFU, maximum at 4 weeks, make them valuable predictors of wound healing. However, further, more extensive studies are required to establish a concrete relationship.

Extreme cooling of 12.5 °C triggered by Typhoon Fungwong (2008)

Typhoon Fungwong, a category-2 but deadly typhoon in the 2008 Pacific typhoon season, made landfall first on Taiwan and then on Southeast China. During its approach toward Taiwan, it triggered an extreme sea surface temperature (SST) drop of 12.5 °C, which was the strongest SST drop recorded by Longdong buoy northeast of Taiwan coast from 1998 to 2017. In this study, including moored buoy temperature measurements, Argo float temperature profiles, satellite-observed SSTs, and a suite of numerical experiments performed using the Regional Ocean Modeling System were used to unveil the detailed processes of how Fungwong triggered such an extreme cooling. Subsequently, the source of the cold waters feeding the extreme cooling, possible mechanisms triggering the cooling, and consequential effects of cooling on the ambient ocean environment were systematically investigated. Results show that the extreme cooling was triggered mainly by a process of uplift of subsurface cold water tied to shore-ward Kuroshio intrusion driven by easterly/northeasterly winds and consequential entrainment mixing, while coastal upwelling driven by persistent longshore (southerly) winds plays a minor role. Nevertheless, the southerly winds still help the enhancement of entrainment mixing and thus the sea surface cooling. Finally, modeled float trajectories with temperature tracers identified where the cold water goes and indicate that the temperature drop might extend all the way toward the south end of Japan (Kyushu) along the flowing path of Kuroshio.

The effect of installing different arrangements of aluminum fins on the photovoltaic performance

One of the significant obstacles for improving the photovoltaic (PV) performance and lowering their surface temperature are the cost, durability and simplicity of cooling systems. Regular aluminum fins have been added in various configurations to the back surface of a PV panel in order to reduce the PV surface temperature and improve the output power. The experimental set-up consists of four photovoltaic panels. PV-1 was used as a baseline, and PV-2 was utilized with longitudinal fins and exposed to natural air cooling. PV-3 was employed to offer forced air cooled at different air velocities with similar longitudinal fins. PV-4 was used with forced air cooling at various air velocities and fins installed in an S shape arrangement. The largest percentage of temperature drops on the PV surface was achieved by the PV-3 with longitudinal fins and forced air cooling. Panels PV-2, PV-3, and PV-4, respectively, have surface temperature drops of 5.48%, 11.86%, and 9.57% in comparison with the baseline panel PV-1. The output power of PV-3 panel having longitudinal fins and forced air cooling increased by 5.42% compared to the baseline PV-1. Additionally, it will be possible to use the heat that absorb by the cooling medium, air, for other purposes.

Comprehensive Satellite Observations and a Numerical Study of a Wintertime Shallow Sea Smoke Event in the Yellow Sea

Abstract A winter storm triggered a significant sea smoke with the northwesterly wind to the Yellow Sea, China, on 7 January 2021. The ocean responses to this event lasted about 3 days. Satellite observations show that the sea surface temperature dropped from 5.7° to 4.7°C on the following day and then recovered to the previous level; the chlorophyll-a, a bio-growth indicator, increased from 3.6 to 3.9 mg m−3 due to cooling-induced coastal upwelling between 7 and 9 January. Two buoys measurements showed that the air temperature dropped to −13.3°C and high relative humidity with a maximum value of 89.0% above the sea surface, creating favorable conditions for sea smoke generation. A Regional Ocean Modeling System (ROMS) and Weather Research and Forecasting (WRF) Model coupled model with the Goddard Chemistry Aerosol Radiation and Transport (GOCART) chemical module was implemented to reproduce this sea smoke phenomenon and analyze the air–sea interaction. The 20°C temperature difference between extreme cold air (−13.3°C) and the relatively warm stable sea surface (4.7°–5.7°C) enhanced the seawater evaporation. In addition, we suppose the concentration of sea salt, a kind of condensation nucleus, with a particle diameter of 0.5–1.5 μm above the sea surface increased quickly on 7 January. The boiling-water-like sea surface was imaged on a synthetic aperture image. We developed an image analysis method to describe the cell-shaped texture characteristics imaged by Synthetic Aperture Radar (SAR). We also found that the sea surface imprints of sea smoke are governed by the thermal, not the dynamical instability. Significance Statement On 7 January 2021, a significant sea smoke event happened in the Yellow Sea. The ocean response to the event lasted 3 days. First, on a synoptic scale, this study presents the comprehensive satellite observations of the sea surface temperature drop and chlorophyll-a increase associated with the sea smoke. Second, a coupled air–sea interaction model with the Goddard Chemistry Aerosol Radiation and Transport (GOCART) chemical module was implemented to reproduce this sea smoke phenomenon and identify which condensation nucleus induced such heavy sea smoke. Third, we developed an image analysis method to analyze high-resolution synthetic aperture radar images and found that the sea surface imprints of sea smoke are governed by the thermal, not the dynamical instability.

Novel concept design of low energy hybrid battery thermal management system using PCM and multistage Tesla valve liquid cooling

To challenge the continuous operation performance of high energy density lithium-ion batteries at different ambient temperatures. A battery thermal management system combining Multi-stage tesla valve liquid cooling and Phase change material (MP) is proposed. After verification of the accuracy of the thermal model based on experimental measurements, numerical studies are performed at the end of 2C rate discharge. In addition, based on general full factorial design method, Kriging approximation model is used to construct complex nonlinear hybrid model between the spacing between batteries, the number of MSTV channels, coolant velocity and the performance of MP (pressure drop, standard deviation of surface temperature, and maximum temperature). At the same time, to avoid falling into local solutions, the adaptive simulated annealing (ASA) global search algorithm is integrated to optimize high-dimensionality multi-objective structural settings. The simulation results show that the designed MP-BTMS is connected with water/ethanol coolant and the inlet velocity is 0.193 m/s, the maximum temperature, standard deviation of surface temperature and pressure drop of the battery pack at 33.12 °C, 1.50 ℃ and 647.8 Pa, respectively. Finally, the optimised MP is used in continuous depth discharge conditions, as well as a range of simulation tests. The superiority of the optimum battery thermal management system in different application scenarios (liquid cooling/heating) is also verified. The cooling performance indicates that the use of MP reduces the total energy consumption required for coolant circulation by 79.9% compared to conventional BTMS. Moreover, it is found that at ambient temperature (Tamb = -10 °C), the use of MP can keep the battery module warm twice as long compared to conventional BTMS. This means that MP can significantly delay the temperature drop during cold stops of EVs, thus reducing the energy required for active battery heating after short-term parking.