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Passive radiative cooling materials are widely recognized as attractive innovations for reducing emissions and expanding life-saving cooling access. Despite immense research attention, the adoption of such technologies is limited largely due to a lack of scalability and cost compatibility with market needs. While paint and coating-based approaches offer a more sensible solution, many demonstrations suffer from issues such as a low solar reflectance performance or a lack of material sustainability due to the use of harmful solvents. In this work, we demonstrate a passive radiative cooling paint which achieves an extremely high solar reflectance value of 98% using a completely water-based formulation. Material sustainability is promoted by incorporating size-dispersed calcium phosphate biomaterials, which offer broadband solar reflectance, as well as a self-crosslinking water-based binder, providing water resistance and durability without introducing harmful materials. Common industry pigments are integrated within the binder for comparison, illustrating the benefit of finely-tuned particle size distributions for broadband solar reflectance, even in low-refractive-index materials such as calcium phosphates. With scalability, outdoor durability, and eco-friendly materials, this demonstrated paint offers a practical passive radiative cooling approach without exacerbating other environmental issues. 

Switchable radiative cooling based on the phase-change material vanadium dioxide (VO₂) automatically modulates thermal emission in response to varying ambient temperature. However, it is still challenging to achieve constant indoor temperature control solely using a VO₂-based radiative cooling system, especially at low ambient temperatures. Here, we propose a reverse-switching VO₂-based radiative cooling system, assisting indoor air conditioning to obtain precise indoor temperature control. Unlike previous VO₂-based radiative cooling systems, the reverse VO₂-based radiative cooler turns on radiative cooling at low ambient temperatures and turns off radiative cooling at high ambient temperatures, thereby synchronizing its cooling modes with the heating and cooling cycles of the indoor air conditioning during the actual process of precise temperature control. Calculations demonstrate that our proposed VO₂-based radiative cooling system significantly reduces the energy consumption by nearly 30 % for heating and cooling by indoor air conditioning while maintaining a constant indoor temperature, even surpassing the performance of an ideal radiative cooler. This work advances the intelligent thermal regulation of radiative cooling in conjunction with the traditional air conditioning technology.

 

Hundreds of studies have explored student evolution acceptance because evolution is a core concept of biology that many undergraduate biology students struggle to accept. However, this construct of “evolution acceptance” has been defined and measured in various ways, which has led to inconsistencies across studies and difficulties in comparing results from different studies. Many studies and essays have offered evaluations and perspectives of evolution acceptance instruments, but publications with a focus on consensus building across research teams is still needed. Further, little attention has been paid to how evolution acceptance instruments may be interpreted differently by students with varied religious backgrounds. Funded by a Research Coordination Network in Undergraduate Biology Education grant from the National Science Foundation, we gathered 16 experts from different disciplinary and religious backgrounds to review current evolution acceptance instruments and create a guide to the strengths and weaknesses of these instruments, including appropriate contexts for using these instruments and their potential weaknesses with different religious populations. Finally, in an attempt to move the field forward, we articulated a consensus definition of evolution acceptance that can be used to guide future instrument development.

 

Passive daytime radiative cooling (PDRC) is a promising energy-saving cooling method to cool objects without energy consumption. Although numerous PDRC materials and structures have been proposed to achieve sub-ambient temperatures, the technique faces unprecedented challenges brought on by complicated and expensive fabrication. Herein, inspired by traditional Chinese oil-paper umbrellas, we develop a self-cleaning and self-cooling oil-foam composite (OFC) made of recycled polystyrene foam and tung oil to simultaneously achieve efficient passive radiative cooling and enhanced thermal dissipation of objects. The OFCs show high solar reflectance (0.90) and high mid-infrared thermal emittance (0.89) during the atmospheric transparent window, contributing to a sub-ambient temperature drop of ∼5.4 °C and cooling power of 86 W m −2 under direct solar irradiance. Additionally, the worldwide market of recycled packaging plastics can provide low-cost raw materials, further eliminating the release of plastics into the environment. The OFC offers an energy-efficient, cost-effective and environmentally friendly candidate for building cooling applications and provides a value-added path for plastic recycling. 

Thermophotovoltaics is a promising technology for heat recovery and has garnered tremendous attention in the past decades. In a thermophotovoltaic system, a selective emitter is required to convert the incoming light in order to emit appropriate photons matched with the bandgap of the PV cell, both avoiding low-energy useless photons and thermalization loss caused by high-energy photons. This work aims to design a metal-based photonic narrowband emitter, and it is composed of tungsten, a refractory material which can withstand the high working temperature of the thermophotovoltaic system. Besides, the advantage of an all-metal emitter is that there is no concern of thermal expansion mismatch. Hexagon and square patterned arrays are numerically analyzed and a parametric study is conducted for different feature sizes, gaps, and pattern heights, leading to an emission peak shift and bandwidth change. Besides, a photonic metal-based emitter is fabricated using a photolithography method, optically characterized and compared with the calculated emissivity spectra. This work sheds light on the research of high-temperature thermal management, energy harvesting and power generation.