Reduction In Surface Temperature Research Articles

Contribution To the Evaluation of Soot Deposit Thickness Evolution and Its Impact on Heat Transfer Within Heavy Diesel Engines: An Innovative Simplistic Procedure

This study deals with a numerical procedure designed and built to evaluate the evolution of soot deposits thickness and their impact on heat transfer for a high-pressure common rail 16V280 marine diesel engine piston. Using a combination of 3D numerical computations and an iterative calculation algorithm, this work reveals the complex relationship between soot deposit, temperature distribution, and piston thermal dynamics. Non-uniform soot deposit distribution is observed, concentrated at the piston bowl peripheral regions. This distribution aligns with theoretical expectations, indicating the influence of the swirl effect. The presence of soot deposits alters the temperature distribution, implying displacement of high-temperature zones towards the bowl region of the piston. The reduction in surface temperature of approximately 14%, is attributed to the lower heat transfer coefficient of deposited layers. This greatly influences the distribution of thermo-mechanical stresses of the piston. The proposed procedure offers an approach to assess the impact of soot deposit on heat transfer. In addition, this study contributes to a better understanding of realistic piston conditions and addresses the challenges introduced by soot deposits in heavy-duty diesel engines by combining the proposed procedure with investigations based on CFD software tools.

Experimental and numerical study on the thermal performance of earthbag-wall units incorporated with phase change materials

The demand for temporary housing for refugees and displaced communities has led to the development of earthbag buildings. While these structures are affordable and sustainable, they often struggle with thermal discomfort in extreme climates. This study aims to examine the integration of phase change materials (PCM) into earthbag walls to improve thermal performance. The research involved incorporating paraffin wax and microencapsulated PCM into scaled-down earthbag walls, with their performance evaluated in a controlled environment. The results were validated against a numerical simulation model developed in EnergyPlus. The study revealed significant thermal improvements with PCM integration. Wall-2, with paraffin wax A31, demonstrated a surface temperature reduction of up to 1.9 °C, while Wall-3, with microencapsulation Inertek26, showed a decrease of 2.4 °C compared to the reference wall. A parametric analysis highlighted the importance of PCM layer thickness. Specifically, Wall-2 with a 6 cm paraffin wax layer achieved a maximum reduction of 4.0 °C compared to the base case. The study identified the transition temperature of PCM as a critical factor in thermal performance, with paraffin wax A31 emerging as the optimal choice. Placing the PCM layer on the interior surface of the wall was more effective than exterior placement. Overall, PCM integration in earthbag walls offers a promising solution to enhance thermal comfort in temporary housing, addressing the critical needs of refugees and displaced communities. This research fills existing gaps in thermal comfort in temporary housing and demonstrates the potential of PCM as an innovative passive design strategy.

Fabrication of Multifunctional Tents Using Canvas Fabric.

Herein, this study was compiled to investigate a suitable solution for the fabrication and development of the multifunctional defense tent from previously reported research. The military always needs to protect their soldiers and equipment from detection. The advancement of infrared detection technology emphasizes the significance of infrared camouflage materials, reducing thermal emissions for various applications. Objects emit infrared radiation detectable by devices, making military targets easily identifiable. Infrared camouflage mitigates detection by lowering an object's infrared radiation, achieved by methods such as reducing surface temperature, which is crucial in designing military tents with infrared (IR) camouflage, considering water repellency and antibacterial features. Water repellency, as well as antimicrobial properties, in army tents is also important as they have to survive in different situations. All these problems should be addressed with the required properties; therefore, the authors try to introduce a new method from which multifunctional tents can be produced through economical, multifunctional, and sustainable materials that have IR protection, water repellency, ultraviolet (UV) protection, air filtration and permeability, and antimicrobial properties. There is still no tent that performs multiple functions at a time, even those functions that do not correlate with each other such as water repellency, IR protection, antimicrobial, and air permeability. So, a multifunctional tent could be the solution to all these problems having all the properties discussed above. In this study based on the literature review, authors concluded a method for the required tent for canvas fabric coated with zinc sulfide (ZnS), graphene oxide (GO), and zinc oxide (ZnO), or these materials should be incorporated in fiber formation because fiber composition has more impact. These multifunctional tents will be very beneficial due to their multifunctions like weather resistance, durability, and long life. These would help the army in their missions by concealing their soldiers and equipment from detection by cameras and providing filtered air inside the tent in case of gases or explosions. The proposed method will help to fulfill the stated and implied needs of customers.

A comparison study of heat dissipation module between the consolidated and unconsolidated porous structures for thermoelectric cooler

The heat dissipation of a thermoelectric cooler plays an important role in its cooling performance. Herein, a comparison study on heat dissipation modules between the consolidated and unconsolidated porous structures for single phase and solid–liquid phase change is done numerically. The governing equations for analyzing the heat transfer behavior and performance of thermoelectric cooling are written and solved. The effects of porosity and the number of cells or blocks on the cooling performance and cold surface temperature are investigated. The enthalpy method is applied to solve the problem of solid–liquid phase change. The obtained results clearly demonstrated that the phase change material can significantly reduce the cold surface temperature and enhance the transient COP of a thermoelectric cooler. The maximum increases in transient COP for the consolidated structure reach 35.5 % and 43.6 % for porosities of 0.75 and 0.95, while these values are 55.8 % and 54.8 % for the unconsolidated structure. The maximum reduction in the cold surface temperature nearly is 17.9 K. The findings can provide a theoretical basis for the optimization of the heat dissipation module of a thermoelectric cooler by using phase change material.

Improving fluid flow and heat transfer of cryogen spray cooling using sweeping cold air jet

Industrial growth has led to increased electronic component integration, resulting in higher working temperatures and technological failures. Cryogen spray cooling (CSC) could reach cryogenic temperatures with fast-responding, but its heat transfer limitation due to liquid film deposition is potentially challenging. In this study, CSC cooling is incorporated with either a cold air jet (CAJ) or a sweeping jet (SWJ) to enhance heat and fluid flow. A K-type thermocouple is used for measuring the surface temperature, while the improved Duhamel theorem is used to estimate the heat flux. The spray and film intensities are recorded through the Mie-scattering methodology via high-speed camera. The results demonstrated that the CAJ/SWJ exhibited a significant reduction in surface temperature and film intensity, enhanced heat dissipation and spray efficiency compared to CSC cooling. More precisely, it demonstrated a 26%–36% heat transfer coefficient improvement, along with a 52% increase in the corresponding time of the critical heat flux. Meanwhile, the CAJ/SWJ intensifies heat transfer during film and transition boiling, inspired by the fast liquid film evaporations. In contrast, the SWJ is much preferred due to its wider and stable coolant coverage throughout film evaporation, as seen by its greater heat transfer coefficient. The combined results demonstrated the need to promptly eliminate the deposited film, as it holds the potential to serve as a pivotal resolution for the advancement of thermal management technology.

Diurnal Warm Layers in the Ocean: Energetics, Nondimensional Scaling, and Parameterization

Abstract Diurnal warm layers (DWLs) form near the surface of the ocean on days with strong solar radiation, weak to moderate winds, and small surface-wave effects. Here, we use idealized second-moment turbulence modeling, validated with large-eddy simulations (LES), to study the properties, dynamics, and energetics of DWLs across the entire physically relevant parameter space. Both types of models include representations of Langmuir turbulence (LT). We find that LT only slightly modifies DWL thicknesses and other bulk parameters under equilibrium wave conditions, but leads to a strong reduction in surface temperature and velocity with possible implications for air–sea coupling. Comparing tropical and the less frequently studied high-latitude DWLs, we find that LT has a strong impact on the energy budget and that rotation at high latitudes strongly modifies the DWL energetics, suppressing net energy turnover and entrainment. We identify the key nondimensional parameters for DWL evolution and find that the scaling relations of Price et al. provide a reliable representation of the DWL bulk properties across a wide parameter space, including high-latitude DWLs. We present different sets of revised model coefficients that include the deepening of the DWL due to LT and other aspects of our more advanced turbulence model to describe DWL properties at midday and during the DWL temperature peak in the afternoon, which we find to occur around 1500–1630 local time for a broad range of parameters.

Effects of intermediate ZrC-TaC layer on ablation resistance and mechanism of (Zr, Hf)C solid solution coating at 2700 °C

An intermediate ZrC-TaC layer was incorporated into the (Hf, Zr)C/SiC coating to enhance its ablation resistance at high temperatures. The impact of this intermediate layer on the ablation resistance and mechanism of the (Zr, Hf)C solid solution coating was analyzed at a temperature of 2700 °C. Due to the formation of gradient multi-layer structure of the (Hf, Zr)C/ZrC-TaC/SiC coating, (Hf, Zr)C/ZrC-TaC/SiC triple-layer coating exhibits superior ablative property than (Hf, Zr)C/SiC double-layer coating. After 20 s ablation at about 2700 °C, the linear and mass ablation rates of double and triple-layer coatings were 0.0030 mm/s, 0.0108 g/s, and −0.0030 mm/s, 0.0074 g/s, respectively. The enhanced ablative property was attributed to the positive role of the prepared ZrC-TaC middle layer, which not only relieves the CTE mismatch between the layers, but also stimulates the formation of continuous (Hf, Zr)O2 protective outer layer and reduction of surface temperature during ablation.

Exploring the potential of phosphorescence for mitigating urban overheating: First time representation in an Urban Canopy Model

Phosphorescence (PP) has emerged as a promising passive cooling solution for the built environment, characterized by its ability to emit radiation persistently after photon absorption, thereby enhancing the solar radiation rejection capability and effective albedo of the surface. While various compounds have shown excellent properties for energy-saving purposes, assessing their benefits for the built environment towards their actual implementation still remains a challenge. To bridge the gap between laboratory-scale characterizations and real-world applications, this study employs the Princeton Urban Canopy Model (PUCM) to assess the surface cooling potential of PP coatings. This research represents the first numerical modeling of phosphorescence, extrapolating findings from experimentally validated parameters to conditions and scale of real cities. Results demonstrate the substantial capacity of PP to ameliorate surface overheating in urban areas, potentially reducing surface temperatures by up to −2.6 °C when optimized. Additionally, material optimization emerges as a crucial factor for exploiting the potential of phosphorescence in mitigating urban overheating, highlighting its strategic relevance for the urban canopy environment.

Improving Roof Surface Temperature Control Using Heat-Reflective Inorganic Composition for Paint and Coating Application

Abstract The increasing global temperatures and thermal islands have made cooling living spaces a pressing issue. Climate change and global energy use cause thermal islands. Greenhouse gas emissions and increasingly expensive and scarce energy supplies are causing disruptive global climate change. The use of energy, heat production, and greenhouse gas emissions caused by building air-conditioning increase the demand for cooling in developed environments. The dearth of sufficient electrical infrastructure for cooling buildings has increased summertime fatalities, including in places such as South Asia and Sub-Saharan Africa. Energy efficiency mitigates the rising cost of energy by reducing those emissions. The rise in surface temperature due to sunlight absorption needs to be reradiated to the sky, or it will conduct through roof spaces toward the ceiling and radiate downwards through insulation batts. Passive cooling technologies, which are environmentally friendly substitutes for extensions of aggressive cooling techniques can solve these problems. In this instance, we focus on the passive daytime radiative cooling of building envelopes and suggest that inorganic composition-based paints are well-suited for use in buildings worldwide. Selective absorption or scattering of light alters the appearance of the coating through inorganic composition. The present investigation focuses on incorporating various inorganic compositions into paint and reducing surface temperature after applying it to walls.

Meta-pragmatic investigation of passive strategies from ‘UHI– climatology’ nexus perspective with digital twin as assessment mechanism

A global phenomenon identified 200 years ago as Urban Heat Island (UHI) effect gained popularity as the sheer contributor to the precipitous temperature gradient between rural and urban interface, instigating excess heat gain and associated ill effects on the urban dwellers. UHI is a function of many interrelated geographical, ecological, and economic parameters that require differential treatment in determining the antecedent impacts. This transdisciplinary review assessed the passive strategies (vegetation, cool roofs, cool pavements, and green roofs) from 83 studies that employed a numerical simulation approach to combat UHI. On average, vegetation and cool/green roofs can reduce ambient temperature by 3–5 ​°C, while cool pavements help to reduce surface temperature by 5 ​°C. All passive strategies also reveal it can reduce buildings' energy demand by 4–10%. However, the current methodological framework for evaluating UHI is quite fragmented, using multiple software and estimates only Surface Urban Heat Island (SUHI), ignoring Canopy Urban Heat Island (CUHI), Boundary Urban Heat Island (BUHI), and the nexus of ‘UHI-Climatology,’ which is linked to regional and global climate change, failing to model UHI and its complex connection to climate change accurately. The review found that the efficacy of passive strategies is a function of factors ranging from location, cloud cover, and soil type to simulation accuracy; hence, while these passive strategies alleviate outdoor temperature in one place, they can cause counterproductive impacts in another region. Therefore, as a postlude, the paper explores an alternative methodological framework for evaluating the nexus of UHI-Climatology using digital twin technology, thus espousing better mitigation strategies.

Urban green spaces and their impact on environmental health: A Global Review

Urbanization has become an irreversible global phenomenon, with a majority of the world's population residing in cities. As urban areas expand, the significance of incorporating green spaces into these landscapes is paramount for environmental health. This study provides a concise overview of a global review that explores the multifaceted impact of urban green spaces on sustainability, well-being, and ecological balance. Urban green spaces play a crucial role in biodiversity preservation, acting as vital habitats for diverse plant and animal species. These spaces contribute to the maintenance of urban ecosystems, fostering ecological balance in densely populated areas. The presence of varied flora and fauna supports environmental health by enhancing biodiversity and promoting a more sustainable urban environment. One of the significant contributions of urban green spaces is their role in improving air quality. Through the natural process of photosynthesis, plants absorb pollutants and release oxygen, serving as an effective filtration system. Trees, in particular, act as natural air purifiers, reducing the concentration of airborne particles and pollutants. This contributes to enhanced air quality, mitigating the adverse effects of urban pollution on environmental health. Urban green spaces also play a pivotal role in temperature regulation, combating the phenomenon of urban heat islands. By providing shade and reducing surface temperatures, greenery helps create a cooler and more comfortable urban living environment. This temperature regulation not only contributes to the well-being of residents but also addresses the challenges posed by rising temperatures in urban areas. Beyond environmental considerations, access to urban green spaces has profound effects on the mental and physical well-being of urban dwellers. These spaces serve as outlets for recreation, exercise, and relaxation, contributing to stress reduction and improved mental health. Additionally, urban green spaces act as hubs for social interaction and community engagement, fostering a sense of belonging and strengthening social cohesion. In conclusion, this global review emphasizes the pivotal role of urban green spaces in promoting environmental health through biodiversity preservation, air quality improvement, temperature regulation, and enhancing overall well-being. Recognizing the multifaceted benefits of these spaces is crucial for guiding sustainable urban development practices worldwide.

Effects of smoke on marine low clouds and radiation during 2020 western United States wildfires

Biomass burning aerosols (BBAs) influence the climate directly by scattering and absorbing sunlight and indirectly by changing the cloud properties through serving as cloud condensation nuclei (CCN) or ice-nucleating particles (INPs). Here we used the WRF-Chem model to simulate the transport of BBAs and their interactions with clouds and radiation during the western United States wildfires in September 2020. The simulated cloud and aerosol fields are comparable to the satellite observations from CALIPSO and MODIS. It is shown that smoke exerts negative radiative effects over both ocean and land. Over the nearly cloudless land, the negative radiative effect is caused by aerosols reflecting shortwave radiation. However, over the ocean covered by stratocumulus, aerosol-cloud interaction (ACI) induces a significant negative radiative effect (−25.6 W/m2 on average), because the reduction of droplet radius not only increases the brightness of clouds and prolongs their lifespan, but also cools their surroundings and increases relative humidity, which in turn increases cloud water content. On the contrary, aerosol-radiation interaction (ARI) leads to a positive radiative effect (+10.3 W/m2 on average) over the oceanic regions due to the absorption of sunlight reflected by low clouds and a slight decrease in cloud water. In our research, the counterclockwise vortex over the Northeast Pacific transports the smoke to remote regions and lifts the smoke to 4–8 km height. This results in a wide-ranging impact of the smoke on clouds and radiation, yet it diminishes the magnitude of ARI's effect on marine stratocumulus. Moreover, over ocean, ARI results in cooling at the cloud top and warming close to the sea surface, leading to a rise in marine stratocumulus height. These vertical atmospheric adjustments within the PBL differ from the reduced surface temperature with suppressed PBL over terrestrial regions.

The effect of forest cover changes on the regional climate conditions in Europe during the period 1986–2015

Abstract. Afforestation affects the earth's climate system by changing the biogeochemical and biogeophysical characteristics of the land surface. While the regional effects of afforestation are well understood in the tropics and the high latitudes, its climate impact on the midlatitudes is still the subject of scientific discussions. The general impact of afforestation on the regional climate conditions in Europe during the last decades is investigated in this study. For this purpose, regional climate simulations are performed with different forest cover fractions over Europe. In a first simulation, afforestation in Europe is considered, while this is not the case for a second simulation. We focus on the years 1986–2015, a period in which the forest cover in Europe increased comparatively strongly, accompanied by a strong general warming over the continent. Results show that afforestation has both local and non-local effects on the regional climate system in Europe. Due to an increased transport of turbulent heat (latent + sensible) into the atmosphere, afforestation leads to a significant reduction of the mean local surface temperatures in summer. In northern Europe, mean local surface temperatures were reduced about −0.3 K with afforestation, in central Europe about −0.5 K, and in southern Europe about −0.8 K. During heat periods, this local cooling effect can reach −1.9 K. In winter, afforestation results in a slight local warming in both northern and southern Europe because of the albedo effect of forests. However, this effect is rather small and the mean temperature changes are not significant. In the downwind direction, locally increased evapotranspiration rates with afforestation increase the general cloud cover, which results in a slight non-local warming in winter in several regions of Europe, particularly during cold spells. Thus, afforestation had a discernible impact on the climate change signal in Europe during the period 1986–2015, which may have mitigated the general warming trend in Europe, especially on the local scale in summer.

Remote Sensing and Field Measurements for the Analysis of the Thermal Environment in the “Bosco Verticale” Area in Milan City

The trend of urbanization nowadays has caused serious issues related to climate. One of the most important ones is that of the ‘Urban Heat Island (UHI)’ and it occurs in major cities throughout the world. The most important categories, and therefore the most studied ones, are the canopy urban heat island (CUHI) and surface heat island (SUHI). The aim and the novelty of the current study was to assess different remote sensing approaches to detect the thermal environment of an open area inside a large city. The study was undertaken in an urban area with green spaces, in the Bosco Verticale area in the city of Milan, during the spring and summer period of 2021. The area is characterized by different types of cover materials, which were investigated in terms of surface temperature under shaded and non-shaded conditions. Both field measurements and remote sensing techniques were applied. Remote sensing techniques included downscaling techniques and the usage of different split-window algorithms applied on the Landsat8 satellite sensor data. The land surface temperature (LST) extracted from remote sensing methods was compared with the surface temperature derived from in situ measurements. For the needs of the study, both in situ measurements and the collection of meteorological data from different fixed meteorological stations throughout the city of Milan were carried out. The results revealed the significance of greenery presence inside the urban environment, as a comparison of the meteorological data across the urban area of Milan showed that the areas with a low presence of greenery were found to be warmer than those with a higher presence of green elements. Concerning the field measurements in the study area, the results showed a significant reduction in both surface and air temperature in shaded places. On the other hand, the presence of conventional artificial materials in sunny areas led to relatively high values of both surface and air temperature. The downscaling method showed satisfying results in terms of average LST values; however, some discrepancies appeared in terms of the RMSE index. The application of split-window algorithms has shown that some forms of the ‘Generalized split-window algorithm’ and some forms of the ‘Jimenez-Munoz algorithm’ presented better performance among the studied algorithms. Comparing the LST values derived from the most representative algorithm, the ‘Du, Wan algorithm’, with those derived from downscaling methods, it was found to be quite close. However, under shaded conditions, the results derived from the ‘Split-window algorithm’ were found to be more precise. The application of remote sensing techniques in microscale in urban regions should be further studied in future, as they could be an essential tool for observing microclimatic conditions in urban areas and on building scale.

Field temperature performances of in-use permeable sidewalks and asphalt vehicle roads and the potential impacts on apparent temperature and land surface temperature.

Permeable pavements help reduce surface temperatures and have been widely implemented in urban areas. This study utilized an in-use permeable pavement sidewalk in front of a mass rapid transit station in the Taipei city center of Taiwan to determine the actual pavement surface temperature performance. A neighboring asphalt road and impervious pavement were also monitored. With a full year of continuous monitoring, the results showed that the temperature of permeable pavement was 3.7°C lower than that of impervious pavement and 4.5°C lower than that of asphalt pavement in the hot season. The frequent rainfall in spring resulted in the smallest temperature differences between the different pavement types. The cooling effects of permeable pavement differed at the different air temperatures. At air temperatures lower than 15 °C, the differences among pavement surface temperatures were noticeable. However, when the air temperature was higher than 35 °C, the surface temperature of permeable pavement was not different from that of impervious pavement and was greater than 55 °C. Field observations were carried out to determine the effects on the apparent temperature and the future surface temperature of climate change scenarios. The results showed that permeable pavement could reduce the average apparent temperature to near the air temperature, and asphalt pavement could increase the apparent temperature by 1.2°C, assuming that the pavement temperature completely affects the air temperature. With the good prediction ability of the machine learning approach and 15 environmental factors, the preliminary prediction showed the projected surface temperature change in Taipei city in 2033. In the worst-case scenario, the average impervious pavement temperature is as high as 39.12°C, whereas the average permeable pavement temperature is 32.50°C.

Improving energy efficiency in Portuguese buildings: Retrofitting façades with high reflectance finishing coat

The European Union must enhance energy efficiency in its building stock, given that buildings account for up to 40% of the EU's energy consumption. Currently, more than 85% of buildings have been in use for over two decades, with at least 75% lacking energy efficiency. Only 10% of the building stock achieves ‘A’ or ‘B’ ratings in energy performance certificates. To meet energy efficiency standards, retrofitting exterior walls with passive techniques, such as enhancing optical properties, proves highly effective. Employing high reflectance surfaces reduces solar heat absorption, thereby lowering cooling energy use. This study examines the impact of reducing surface temperature through an external thermal insulation system with a high reflectance finishing coat during building envelope renovation in various climatic zones in Portugal. Preliminary findings indicate that high reflectance has a more substantial effect on annual heat gain for moderately insulated walls than well-insulated ones. The effect varies with maximum air temperature, especially in hot summers. A change in reflectance can improve heat gain reduction, especially considering the cost of retrofitting with insulation materials. An optimal balance between reflectance and thermal resistance is key to achieving lower surface temperatures and reducing cooling energy demands for Portuguese climates.

ASPHALT BINDERS EMPLOY VARIOUS ORGANIC ADDITIVES: PHYSICAL AND RHEOLOGICAL QUALITIE

Several studies aim to reduce surface temperatures and improve the performance of hot mix asphalt. These studies have occurred to reduce the global warming phenomena and economic concerns. We're researching how organic materials affect the viscosity of modified asphalt. Asphaltan A, Asphaltan B, Asphaltan C, and T-grade are organic additives.  temperatures with the asphalt binder were employed in the current study.  These organic additives were used to improve the characteristics of hot-mix asphalt. In addition, it increases the durability, and lifespan of pavement and reduces mixing and compaction temperatures. A penetration grade bitumen of 40/50 was used in this study. Then, pure bitumen was added to the organic additives to modify binders containing varying concentrations of each additive. Physical properties were performance at different levels of additives. In the research, conventional bitumen/asphalt should be adjusted due to climate conditions, strong traffic loads, and growing axial loads. As a result, asphalt mixtures comprehending bitumen with a high penetration index are less prone to low-temperature cracking and irreversible deformation. Traditional asphalt studies found that bitumen samples with the softening point of warm mix asphalt additives were greater rate, and were less susceptible to temperature changes. The introduction of organic compounds increased the penetration and softening point of the asphalt substantially. This indicated that the stiffness and thermal expansion of the binder had gotten better.

Thermal aspects of living walls: a review on the influence of different structural materials and plant species

The use of living walls, a type of vertical garden, promotes the reduction of surface temperatures in buildings, and the choice of the appropriate plant species can contribute to optimizing the passive cooling of buildings. To better understand this issue, this study aimed to evaluate the thermal performance of living walls. For this purpose, a systematic review was conducted in the Scopus database using the keywords 'green wall, living wall, vertical garden, and 'thermal performance' present in the titles of articles, in the time frame from 2011 to 2021, and in the fields of architecture and urbanism; engineering; environmental science; agriculture; and biological sciences. Sixty-seven articles were identified, and after screening for articles relevant to the topic, 29 were selected. The analysis of the results showed that the layers, the type of material (PVC and felt), and the species used influence the system's performance. Regarding the species, only 11 articles identified the names, and only 4 evaluated the thermal performance of each one. The PVC-type structure proved to be more efficient, with a longer lifespan and durability of vegetation, as it provides a larger area for root development.

Buffering Effect of Atmosphere–Ocean Coupling on Intensity Changes of Tropical Cyclones Under a Changing Climate

AbstractThe effect of atmosphere–ocean coupling on intensity changes of tropical cyclones (TCs) under global warming was examined using a regional high‐resolution three‐dimensional atmosphere–ocean coupled model. A storyline event attribution approach was applied to four historical intense TCs in the western North Pacific. The results indicate that atmosphere–ocean coupling buffers TC intensification as global warming progresses. This buffering effect increased as storms traveled northward. Moreover, the effect intensified as warming progressed, because reductions in sea surface temperature induced by the storm increased as the storm strengthened in future warmer climates. The magnitude of the buffering effect depended on the storm's size and translation speed; a large, slow‐moving storm had significant resilience against global warming, whereas a compact, fast‐moving storm was sensitive to global warming. A high‐resolution atmosphere–ocean coupled model is important for more reliable future projections of TC intensity under the changing climate.

Diamond-SiC composite substrates: A novel strategy as efficient heat sinks for GaN-based devices

Combining the structural advantages of SiC with super thermal conductivity of diamond to construct an efficient heat dissipation substrate for GaN-based transistors is a promising strategy to solve the self-heating problem. Herein, a scheme for direct growth of polycrystalline diamond on 4H–SiC substrate, followed by thinning of the 4H–SiC substrate to an optimum thickness, is designed and implemented. Diamond-SiC composite substrates consisting of 200 μm 4H–SiC and 200 μm diamond are fabricated. The simulation of GaN devices is carried out to provide theoretical support for device fabrication. Then, compatible with established epitaxial and device manufacturing technology on SiC substrate, GaN devices are fabricated on diamond-SiC composite substrates. A 52.5 °C reduction in surface temperature and about 41 % reduction in thermal resistance of the improved heat dissipation structures are exhibited, by contrast with GaN-on-SiC technology at base temperature of Tb = 25 °C and dissipation power of Pdiss = 7.2 W mm−1. The stable output characteristics and reliability of GaN-on-diamond/SiC structures are confirmed at high temperatures. This work is anticipated to afford a promising heat dissipation strategy for devices with high power density and illuminate a new perspective on exploring and constructing novel composite substrates with diamond.