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Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 2
Author(s):  
Wenchang Sun ◽  
Yueming Hou ◽  
Xu Zhang

A novel type of bi-functional microencapsulated phase change material (MEPCM) microcapsules with thermal energy storage (TES) and carbon dioxide (CO2) photoreduction was designed and fabricated. The polyaniline (PANI)/titanium dioxide (TiO2)/PCN-222(Fe) hybrid shell encloses phase change material (PCM) paraffin by the facile and environment-friendly Pickering emulsion polymerization, in which TiO2 and PCN-222(Fe) nanoparticles (NPs) were used as Pickering stabilizer. Furthermore, a ternary heterojunction of PANI/(TiO2)/PCN-222(Fe) was constructed due to the tight contact of the three components on the hybrid shell. The results indicate that the maximum enthalpy of MEPCMs is 174.7 J·g−1 with encapsulation efficiency of 77.2%, and the thermal properties, chemical composition, and morphological structure were well maintained after 500 high–low temperature cycles test. Besides, the MEPCM was employed to reduce CO2 into carbon monoxide (CO) and methane (CH4) under natural light irradiation. The CO evolution rate reached up to 45.16 μmol g−1 h−1 because of the suitable band gap and efficient charge migration efficiency, which is 5.4, 11, and 62 times higher than pure PCN-222(Fe), PANI, and TiO2, respectively. Moreover, the CO evolution rate decayed inapparently after five CO2 photoreduction cycles. The as-prepared bi-functional MEPCM as the temperature regulating building materials and air purification medium will stimulate a potential application.


2021 ◽  
Author(s):  
Farida Hanna Campbell

Viruses ensure the vital redistribution of nutrients to maintain sustainability in an ecosystem. This includes repair and survival, growth and evolution thanks to the efficient nutrient recycling and infectious rates of viruses throughout a stressed-ecosystem. If evolution in space–time can be defined by multiple planes which change position according to the evolution rate of the habitat, then the locations and volumes of returning chronic infectious viruses will appear in a logical predictable fashion based on the lissajous trajectory based on thermodynamic modeling.


2021 ◽  
Vol 2021 (4) ◽  
pp. 4818-4823
Author(s):  
JAROSLAV ROJICEK ◽  
◽  
DAGMAR LICKOVA ◽  

An evolutionary procedure for multiple materials is presented. A material is selected due to an allowable stress interval for the material. The presented method includes a mesh-independent filter. The proposed algorithm is applied to three examples with four or five materials. In the presented examples, the effect of an evolution rate, a filter setting, and the number of elements, are shown in a simplified way. It is shown that the final topology of structure meets the stress requirements of the materials.


Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5916
Author(s):  
Yiyang Liu ◽  
Jinze Liu ◽  
Hongzhen He ◽  
Shanru Yang ◽  
Yixiao Wang ◽  
...  

In this work, the impact of chemical additions, especially nano-particles (NPs), was quantitatively analyzed using our constructed artificial neural networks (ANNs)-response surface methodology (RSM) algorithm. Fe-based and Ni-based NPs and ions, including Mg2+, Cu2+, Na+, NH4+, and K+, behave differently towards the response of hydrogen yield (HY) and hydrogen evolution rate (HER). Manipulating the size and concentration of NPs was found to be effective in enhancing the HY for Fe-based NPs and ions, but not for Ni-based NPs and ions. An optimal range of particle size (86–120 nm) and Ni-ion/NP concentration (81–120 mg L−1) existed for HER. Meanwhile, the manipulation of the size and concentration of NPs was found to be ineffective for both iron and nickel for the improvement of HER. In fact, the variation in size of NPs for the enhancement of HY and HER demonstrated an appreciable difference. The smaller (less than 42 nm) NPs were found to definitely improve the HY, whereas for the HER, the relatively bigger size of NPs (40–50 nm) seemed to significantly increase the H2 evolution rate. It was also found that the variations in the concentration of the investigated ions only statistically influenced the HER, not the HY. The level of response (the enhanced HER) towards inputs was underpinned and the order of significance towards HER was identified as the following: Na+ > Mg2+ > Cu2+ > NH4+ > K+.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2295
Author(s):  
Simin Yin ◽  
Shun Liu ◽  
Yongfeng Yuan ◽  
Shaoyi Guo ◽  
Zhaohui Ren

In this work, octahedral shaped PbTiO3-TiO2 nanocomposites have been synthesized by a facile hydrothermal method, where perovskite ferroelectric PbTiO3 nanooctahedra were employed as substrate. The microstructures of the composites were investigated systemically by using XRD, SEM, TEM and UV-Vis spectroscopy. It was revealed that anantase TiO2 nanocrystals with a size of about 5 nm are dispersed on the surface of the {111} facets of the nanooctahedron crystals. Photocatalytic hydrogen production of the nanocomposites has been evaluated in a methanol alcohol-water solution under UV light enhanced irradiation. The H2 evolution rate of the nanocomposites increased with an increased loading of TiO2 on the nanooctahedra. The highest H2 evolution rate was 630.51 μmol/h with the highest concentration of TiO2 prepared with 2 mL tetrabutyl titanate, which was about 36 times higher than that of the octahedron substrate. The enhanced photocatalytic reactivity of the nanocomposites is possibly ascribed to the UV light absorption of the nanooctahedral substrates, efficient separation of photo-generated carriers via the interface and the reaction on the surface of the TiO2 nanocrystals.


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