Search Results (9)

In this study, we present bi-layered hydrogel systems that incorporate different sizes and shapes of gold nanoparticles (nanospheres and nanorods) for potential use in areas such as photoactuators, soft robotics, artificial muscles, drug delivery and tissue engineering. The synthesized nano Au-PNiPAAm/PVA bi-layered hydrogel nanocomposites provide the unique ability to exhibit controlled motion upon light exposure, indicating that the above systems possess the capability of photo–thermal energy conversion. The chosen synthesis approach is a combination of chemical production of gold nanoparticles (AuNPs) followed by gamma radiation formation of crosslinked polymer networks around them, as the final step, which also allows for sterilization in a single technological step. According to the TEM analysis, the gold nanospheres (AuNSs) with mean diameters of around 17 and 30 nm, as well as nanorods (AuNRs) with an aspect ratio of around 4.5, were synthesized and used as nanofillers in the formation of nanocomposites. Their stability within the polymer matrix was confirmed by UV–Vis spectral studies, by the presence of local surface plasmon resonance (LSPR) bands, typical for nanoparticles of various shapes and sizes. Morphological studies (FE-SEM) of hydrogels revealed the formation of a porous structure with PNiPAAm hydrogel as an active layer and PVA hydrogel as a passive layer, as well as a stable interfacial layer with a thickness of around 80 μm. The synthesized bi-layered photoactuators showed a photo–thermal response upon exposure to irradiation of green lasers and lamps that simulate sunlight, resulting in bending motion. This bending response reveals the huge potential of the obtained materials as soft actuators, which are more flexible than rigid systems, making them effective for specific applications where controlled movement and flexibility are essential. Full article

With the intensification of global climate change, buildings in hot climate zones face increasing challenges related to high energy consumption and thermal comfort. Building integrated photovoltaic (BIPV) façades, which combine power generation and energy saving potential, require further optimization in their climate-adaptive design. Most existing studies primarily focus on the photoelectric conversion efficiency of PV modules, yet there is a lack of systematic analysis of the coupled effects of temperature, humidity, and solar radiation intensity on PV performance. Moreover, the current literature rarely addresses the regional material degradation patterns, integrated cooling solutions, or intelligent control systems suitable for hot and humid climates. There is also a lack of practical, climate specific design guidelines that connect theoretical technologies with real world applications. This paper systematically reviews BIPV façade design strategies following a climate zoning framework, summarizing research progress from 2019 to 2025 in the areas of material innovation, thermal management, light regulation strategies, and parametric design. A climate responsive strategy is proposed to address the distinct challenges of humid hot and dry hot climates. Finally, this study discusses the barriers and challenges of BIPV system applications in hot climates and highlights future research directions. Unlike previous reviews, this paper offers a multi-dimensional synthesis that integrates climatic classification, material suitability, passive and active cooling strategies, and intelligent optimization technologies. It further provides regionally differentiated recommendations for façade design and outlines a unified framework to guide future research and practical deployment of BIPV systems in hot climates. Full article

The lithium-ion battery equalization system is a critical component in Low-Earth Orbit (LEO) satellite power supply systems, ensuring the consistency of battery cells, maximizing the utilization of battery pack capacity, and enhancing battery reliability and cycle life. In DC bus satellite power systems, passive equalization technology is widely adopted due to its simple structure and ease of control. However, passive equalization suffers from drawbacks such as complex thermal design and limited operation primarily during battery charging. These limitations can lead to inconsistent control over the depth of discharge of individual battery cells, ultimately affecting the overall lifespan of the battery pack. In contrast, active equalization technology offers higher efficiency, faster equalization speeds, and the ability to utilize digital control methods, making it the mainstream direction for the development of lithium-ion battery equalization technology. Nevertheless, active equalization often requires a large number of switches and energy storage components, involves complex control algorithms, and faces challenges such as large size and reduced reliability. Most existing active equalization techniques are not directly applicable to DC bus satellite power systems. In this study, based on the operational characteristics of LEO satellite power storage batteries, an active–passive hybrid equalization topology utilizing a switching matrix is proposed. This topology combines the advantages of a simple structure, ease of control, and high reliability. Its feasibility has been validated through experimental results. Full article

This review paper aims to present a comprehensive overview of the evaluation, simulation, and control of heating, ventilation, and air conditioning (HVAC) systems in nuclear power plants (NPPs), specifically highlighting their importance in maintaining operational safety, thermal performance, and energy efficiency. The study’s authors summarize recent developments in HVAC technologies, such as passive cooling systems, data-driven energy management frameworks, and intelligent control strategies, to cope with the specific challenges of NPPs. Various passive cooling systems, including heat pipes, thermosyphons, and loop heat pipes, have proven themselves by their ability to remove residual heat from spent fuel pools and reactors power plants with high efficiency. Through experimental studies, they have shown their ability to eliminate operational vulnerability to accidents or guarantee any desired long-term cooling. Intelligent sensor networks allow a more data-driven approach to HVAC control, enabling online energy management frameworks and advanced intelligent control systems. These exhibit considerable promise for optimizing HVAC performance, decreasing energy consumption, and improving operational flexibility in multi-zone systems. Such capabilities are ideal for addressing the dynamic and safety-critical nature of NPPs. They are first enabled by the use of these technologies for real-time monitoring, predictive maintenance, and adaptive control. When applied with advanced HVAC control systems, passive cooling techniques provide an exciting route to improve safety and energy efficiency. An overview of the key findings is that robust thermal management solutions combined with intelligent control and intelligent adaptation are essential when addressing the rapidly evolving demands of nuclear energy systems. This work highlights the priorities in the next generation of nuclear power plants, which should actively pursue seamless integration of out-of-system technologies into existing NPP infrastructures, enabling scalable, cost-effective, and resilient solutions. Full article

Climate change has reduced the comfort of community environments, and there is an urgent need to improve the health and well-being of low-income residents through design and technical measures. Therefore, this paper conducts research in the context of an ongoing social housing renovation project in Aosta, Italy, in a cold winter and hot summer Alpine environment. The study combined interviews, field measurements, and multiple software simulations to analyze the home of an older adult experiencing energy deprivation. The study found that the indoor acoustic environment quality meets the requirements of various sound-related standards. Still, the lighting and thermal environment must be designed to reduce glare and western sun exposure, and the air quality could improve. Residents’ demand for renovation is low technology, low cost, and high comfort. Therefore, suggestions for combining active and passive transformation measures and maximizing the use of climate and resources are proposed. The lighting and thermal environment are optimized based on the green wisdom of the Haylofts building of the Walser family in the Alps: increase ventilation and reduce indoor air age to improve air quality. Overall, a comprehensive assessment of extreme climatic conditions facilitates the quantitative and qualitative study and control of social housing environments, improves occupant comfort, and decarbonizes such social building stock. Full article

Purpose. The problem of heavy metal Cd pollution in the soil is still very serious. The widely used treatment measure is in situ passivation chemical remediation technology. Some studies have shown that the single application of phosphate or silicate can control soil cadmium pollution, but few studies have been conducted on the effect of the thermal activation temperature of nano phosphate and silicate-combined application on the transformation of Cd form in the soil. Materials and methods. Cadmium-contaminated soil was indoor-simulated, after which the 2.0% soil-weight dose of potassium dihydrogen phosphate was mixed with thermal activation nano serpentine or nano zeolite (potassium dihydrogen phosphate: thermal activation nano serpentine or nano zeolite = 1:2) at different temperatures (0, 350, 550, 700, 850 °C) and compared with the simulated cadmium-contaminated soil without adding a mixture of phosphate and silicate; cadmium content in soil was determined by Tessier five-step continuous extraction method after incubating for 0, 7, 14, 28, and 56 d in jars in the constant-temperature box. Results and discussion. Thermal activation temperature of nano phosphate and silicate could reduce the amount of exchangeable Cd content in the soil to a different degree; the content of Cd in carbonate-bound form, Fe–Mn–oxide-bound form, organically-bound form, and residual form increased. The order of effect of nanoscale potassium dihydrogen phosphate and serpentine or zeolite thermal activation temperature on remediation of Cd contaminated soil is nPS₇₀₀-2.0 > nPS₅₅₀-2.0 > nPS₈₅₀-2.0 > nPS₃₅₀-2.0 > nPS₀-2.0, nPF₇₀₀-2.0 > nPF₅₅₀-2.0 > nPF₈₅₀-2.0 > nPF₃₅₀-2.0 > nPF₀-2.0 (n, P, S, and F represent nanometer, KH₂PO₄, serpentine, and zeolite, respectively; 0, 350, 550, 700, and 850 represent different activation temperatures T); 700 °C treatments performed better than other thermal activation temperature treatments, and nPS₇₀₀-2.0 was better than nPF₇₀₀-2.0. Conclusion. Thermal activation temperature of nano phosphate and silicate-combined application can stabilize heavy metal Cd to some extent and promote the transition of Cd from a bioavailable state to a biounavailable state. The results showed that the combined application of thermal activation temperature of nano phosphate and silicate has a certain potential to control soil cadmium pollution. Full article

The building envelope provides thermal comfort, an excellent visual view, and sunlight for the occupants. It consists of two parts: (i) an opaque (non-transparent) part (e.g., walls and roofs) and (ii) a transparent part (e.g., windows, curtain walls, and skylight devices). Recently, the use of fully-glazed facades, especially in large cities, has increased due to their aesthetical and structural advantages. This has led this study to review the performance of the currently passive smart glazing technologies. Phase Change Materials (PCMs) as latent energy storage material is the focus of this review, as well as other individual and combined techniques, including shading systems, solar cells (photovoltaic), and chromogenic (thermotropic and thermochromic) materials. PCM-integrated glazing systems have been extensively studied and rapidly developed over the past several decades from the standpoint of unique system designs, such as passive, active, and passive/active mixed designs, intelligent management, and sophisticated controls. In the academic literature, numerous studies on PCM-integrated building envelopes have been conducted, but a comprehensive review of PCM-integrated GUs combined with other passive and active techniques using dialectical analysis and comparing the climatic conditions of each study using Köppen-Geiger climate classification climate classification has been performed only rarely. Consequently, the primary objective of this study is to reduce this discrepancy for all types of glazing, excluding glazed roofs. This review article also contains literature tables as well as highlights, limitations, and further research suggestions at the end of each subsection. Full article

A lithium-ion capacitor (LiC) is one of the most promising technologies for grid applications, which combines the energy storage mechanism of an electric double-layer capacitor (EDLC) and a lithium-ion battery (LiB). This article presents an optimal thermal management system (TMS) to extend the end of life (EoL) of LiC technology considering different active and passive cooling methods. The impact of different operating conditions and stress factors such as high temperature on the LiC capacity degradation is investigated. Later, optimal passive TMS employing a heat pipe cooling system (HPCS) is developed to control the LiC cell temperature. Finally, the effect of the proposed TMS on the lifetime extension of the LiC is explained. Moreover, this trend is compared to the active cooling system using liquid-cooled TMS (LCTMS). The results demonstrate that the LiC cell temperature can be controlled by employing a proper TMS during the cycle aging test under 150 A current rate. The cell’s top surface temperature is reduced by 11.7% using the HPCS. Moreover, by controlling the temperature of the cell at around 32.5 and 48.8 °C, the lifetime of the LiC would be extended by 51.7% and 16.5%, respectively, compared to the cycling of the LiC under natural convection (NC). In addition, the capacity degradation for the NC, HPCS, and LCTMS case studies are 90.4%, 92.5%, and 94.2%, respectively. Full article

In order to ensure the imaging performance of the aerial optoelectronic platform system in low temperature environment, an active-passive combined thermal control technology was studied. A thermal control finite element model of the aerial optoelectronic platform was established. Additionally, thermal control simulation analysis and experiments under extreme conditions were carried out respectively. The simulation and experimental results showed that the temperature level of the primary mirror is improved above 25 °C by the proposed thermal control technology effectively, meanwhile the temperature gradient of the primary and secondary mirrors are less than 5 °C. The successful implementation of this active-passive combined thermal control technology provides a technical support for the precision thermal control of aerial optoelectronic platforms. Full article