Kai Zhu¹, Hao Chen^1,*, Shuang Wang^1,*, Chuan Yuan^1,2, Bin Cao³, Jun Ni¹, Lujiang Xu⁴, Anqing Zheng⁵, Arman Amani Babadi¹

Journal of Renewable Materials, Vol.11, No.6, pp. 2849-2864, 2023, DOI:10.32604/jrm.2023.026317

Abstract Microalgae biomass is an ideal precursor to prepare renewable carbon materials, which has broad application. The bioaccumulation efficiency (lipids, proteins, carbohydrates) and biomass productivity of microalgae are influenced by spectroscopy during the culture process. In this study, a bilayer plate-type photobioreactor was designed to cultivate Chlorella protothecoides with spectral selectivity by nanofluids. Compared to culture without spectral selectivity, the spectral selectivity of Ag/CoSO₄ nanofluids increased microalgae biomass by 5.76%, and the spectral selectivity of CoSO₄ solution increased by 17.14%. In addition, the spectral selectivity of Ag/CoSO₄ nanofluids was more conducive to the accumulation of nutrients (29.46% lipids, 50.66% proteins, and… More > Graphic Abstract

Wei Chen^1,*, Ao Xu¹, Hejun Zhang¹, Mingquan Sheng¹, Yue Liang¹, Frederic Skoczylas²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1623-1636, 2023, DOI:10.32604/fdmp.2023.025083

Abstract Two different freeze-thaw cycles (FTC) are considered in this study to assess the related impact on gas permeability and micro-pore structure of a mortar. These are the water-freezing/water-thawing (WF-WT) and the air-freezing/air-thawing (AF-AT) cycles. The problem is addressed experimentally through an advanced nuclear magnetic resonance (NMR) technique able to provide meaningful information on the relationships among gas permeability, pore structure, mechanical properties, and the number of cycles. It is shown that the mortar gas permeability increases with the number of FTCs, the increase factor being 20 and 12.83 after 40 cycles for the WF-WT and AF-AT, respectively. The results also… More >

Fulin Wang^*, Xinyang Geng, Zhengping Yuan, Shijiao Yang^*

Journal of Renewable Materials, Vol.11, No.3, pp. 1469-1484, 2023, DOI:10.32604/jrm.2022.024994

Abstract The use of some environmental functional minerals as backfill-modified materials may improve the leaching resistance of cemented uranium tailings backfill created from alkali-activated slag (CUTB), but these materials may participate in the hydration reaction of the cementitious materials, which could have a certain impact on the pore structure of the CUTB, thus affecting its mechanical properties and leaching resistance. In this paper, natural zeolite is selected as the backfill-modified material, and it is added to alkali-activated slag paste (AASP) and CUTB in cementitious material proportions of 4%, 8%, 12%, and 16% to prepare AASP mixtures and CUTB mixtures containing environmental… More >

Peng Zhang¹, Dongsheng Shi^1,*, Ping Han^1,2, Wenchao Jiang^1,3

Journal of Renewable Materials, Vol.11, No.2, pp. 669-688, 2023, DOI:10.32604/jrm.2022.022192

Abstract The destruction of concrete building materials in severely cold regions of the north is more severely affected by freeze-thaw cycles, and the relationship between the mechanical properties and pore structure of concrete with fine aggregate from municipal solid waste (MSW) incineration bottom ash after freeze-thaw cycles is analyzed under the degree of freeze-thaw hazard variation. In this paper, the gray correlation method is used to calculate the correlation between the relative dynamic elastic modulus, compressive strength, and microscopic porosity parameters to speculate on the most important factors affecting their changes. The GM (1,1) model was established based on the compressive… More >

Sheng He¹, Weiqi Leng^2,*, Yuhe Chen¹, Hongchen Li³, Jingpeng Li¹, Zaixing Wu¹, Zizhang Xiao¹

Journal of Renewable Materials, Vol.11, No.1, pp. 321-331, 2023, DOI:10.32604/jrm.2023.022097

Abstract Microwave (MW) drying method was adopted to enhance the liquid permeability of Scots pine lumber. Structure changes were characterized by stereoscope microscope, scanned electron microscope (SEM) and transmission electron microscope (TEM) examination. Pore parameters before and after MW treatment were detected by mercury intrusion porosimetry (MIP) method, and the effect of structure changes on liquid permeability were analyzed. As stereoscope microscope, SEM and TEM examination results shown, macro and micro checks mainly developed at intercellcular of tracheids, intercellular of ray parenchyma and tracheid, while these checks extend main along the radial-longitudinal plane. Pit border destruction, aspirated pits’ orus translocation and… More >

Lixia Guo^1,2,3, Weikai Wang¹, Ling Zhong^1,2,3,*, Yuhang Guo¹

Journal of Renewable Materials, Vol.11, No.1, pp. 423-434, 2023, DOI:10.32604/jrm.2022.022942

Abstract Based on the high sulfur content in titanium gypsum, the concept of the calcium-silicon-sulfur (Ca/Si/S) ratio was proposed. The Ca/Si/S ratio of concrete was adjusted by changing the titanium gypsum, fly ash, and cement content. The effects of different Ca/Si/S ratios on the mechanical properties, hydration products, and concrete microstructure were investigated by nuclear magnetic resonance, uniaxial compression, and scanning electron microscopy. The result shows: (1) The compressive strength of concrete mixed with titanium gypsum increases first and then decreases with the Ca/Si/S ratio decrease. When the Ca/Si/S ratio is 1:0.85:0.10, the strength reaches the peak and is lower than… More > Graphic Abstract

Xiaoling Qu, Xingshuo Yang, Siqi Li, Changan Tian, Zaibo Li, Zhiguang Zhao^*

Journal of Renewable Materials, Vol.10, No.12, pp. 3335-3350, 2022, DOI:10.32604/jrm.2022.020636

Abstract The associated MgO in limestone is believed to affect the volume stability of cementitious materials at room temperature, which limits the utilization of low-grade limestone. In this study, MgO was used as an alkali activator instead of partial CaO to prepare the aerated concrete under hydrothermal conditions. The expansion process was studied to evaluate the influence of the raw materials on the gas forming stability of the slurry. The pore structure (porosity, pore size and its distribution) was analyzed by the image method. The physic-mechanical properties (density, strength, thermal properties) of concrete with the addition of MgO were comprehensively investigated.… More >

Chao Liu^1,2,*, Huawei Liu^2,*, Jian Wu¹

Journal of Renewable Materials, Vol.10, No.5, pp. 1397-1414, 2022, DOI:10.32604/jrm.2022.018386

Abstract In this paper, recycled bricks and recycled concrete were applied to prepare eco-friendly recycled mixed powder (RMP) cementitious material, as a supplementary to replace conventional cement for improve the recycling of construction and demolition waste. Based on the effect of cementitious materials on the hydration of silicate cement, the effects of RMP on the workability, mechanical properties and microstructure of recycled mixed powder concrete (RMPC) with the different replacement ratios and the 8:4 and 6:4 mixing ratio of recycled brick powder (RBP) and recycled concrete powder (RCP) were investigated. The results showed that the fluidity of the mix decreased with… More >

Lei Guo^1,2,3,4, Pingping Chen¹, Lixia Guo^1,2,3,*, Zhilong Xue⁴, Zi Guan¹, Mingru Li¹

Journal of Renewable Materials, Vol.9, No.10, pp. 1805-1819, 2021, DOI:10.32604/jrm.2021.015140

Abstract In order to explore the relationship between the macroscopic properties and pore structure characteristics of baking-free slag-sludge bricks, the compressive strength and water absorption rate using aluminum industrial slag and sludge of different substitution rates were tested. Optical instruments and image analysis software were used to measure the parameters of the pore structure. Specifically, a fractal model was built based on the fractal theory, in which the fractal dimension was used as the characteristic index of the pore structure to analyze the correlation and interaction mechanism between the fractal dimension and the macroscopic mechanical properties. Based on this study, conclusions… More >

Fang Liu¹, Baomin Wang^2,*, Mengsai Wang², Xiaosa Yuan¹

Journal of Renewable Materials, Vol.9, No.4, pp. 723-742, 2021, DOI:10.32604/jrm.2021.013664

Abstract

In this paper, mercury intrusion porosimetry (MIP) is used to test the pore structure of non-dispersible underwater concrete so as to study the influence of pouring and curing environment, age and slag powder on the pore characteristics of concrete, analyze the pore characteristics, porosity and pore distribution of concrete in different hydration stages, and reveal the relationship between pore structure and permeability of concrete. The results show that the pore-size distribution of concrete in fresh water condition is better than that in sulfate environment and mixed salt environment, and therefore, sulfate as well as mixed salt are not conducive to… More >