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Replacing cement with industrial by-products is an important way to achieve carbon neutrality in the cement industry. The purpose of this study is to evaluate the effect of eggshell powder on cement hydration properties, and to evaluate its feasibility as a substitute for cement. The substitution rates of eggshell powder are 0%, 7.5%, and 15%. Studying the heat of hydration and macroscopic properties can yield the following results. First: The cumulative heat of hydration based on each gram of cementitious material falls as the eggshell powder content rises. This is a result of the eggshell powder's diluting action. However, the cumulative heat of hydration per gram of cement rises due to the nucleation effect of the eggshell powder. Second: The compressive strengths of ES0, ES7.5, and ES15 samples at 28 days of age are 54.8, 43.4, and 35.5 MPa, respectively. Eggshell powder has a greater negative impact on the compressive strength. The effect of eggshell powder on the speed and intensity of ultrasonic waves has a similar trend. Third: As the eggshell powder content increases, the resistivity gradually decreases. In addition, we also characterize the microscopic properties of the slurry with added eggshell powder. X-ray Diffraction (XRD) shows that, as the age increases from 1 day to 28 days, hemicaboaluminate transforms into monocaboaluminate. As the content of the eggshell powder increases, FTIR analysis finds a slight decrease in the content of CSH. Similarly, thermogravimetric (TG) results also show a decrease in the production of calcium hydroxide. Although the additional nucleation effect of eggshell powder promotes cement hydration and generates more portlandite, it cannot offset the loss of portlandite caused by the decrease in cement. Last: A numerical hydration model is presented for cement–eggshell powder binary blends. The parameters of the hydration model are determined based on hydration heat normalized by cement mass. Moreover, the hydration heat until 28 days is calculated using the proposed model. The strength development of all specimens and all test ages can be expressed as an exponential function of hydration heat. [ABSTRACT FROM AUTHOR]

To date, carbon utilization within the concrete industry is predominantly revolved around gaseous and liquid carbon dioxide (CO2), with relatively limited research dedicated to the application of solid CO2. This study was the first to use solid CO2 (dry ice) as an additive in alkali-activated slag and fly ash (AASF) to investigate its influences on the alkali-activation process and various property improvements. Two study systems were designed: one with alkali-activated slag (AAS) as the control group and fly ash (FA) added at substitution rates of 10%, 30%, and 50%; and the other with 50% FA alkali-activated materials (AAM) as the control group and dry ice added at substitution rates of 4%, 8%, and 12%. Several tests were conducted on AASF, encompassing assessments of setting time, compressive strength, and durability (electrical resistivity and chloride ion diffusion coefficient). Furthermore, a comprehensive analysis of its microstructure was undertaken, employing analytical techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results showed that FA substitution effectively mitigated the short setting time of AAS; however, the mechanical properties and durability decreased by approximately 50%. When dry ice was added to AAM concrete, it induced a series of physical and chemical effects that altered the kinetics of the hydration reaction of AAM. Specifically, adding dry ice significantly prolonged the setting time of AAMs. Moreover, this addition did not damage the mechanical properties or durability of AAS(F). [ABSTRACT FROM AUTHOR]

Production of omega-3polyunsaturated fatty acids concentratesfrom oil of Schizochytrium limacinumwas optimizedto obtain the highest omega-3 polyunsaturated fatty acid (ω-3PUFA)enrichment ratio. In this process, the content of docosapentenoicacid (DPA), the content of docosahexenoic acid (DHA) in the finalproduct, the percentage recovery of the heavy phase, and the ω-3PUFAenrichment ratio were optimized. Single-factor experiments were carriedout to study the effects of evaporator temperature, feeding rate,feeding temperature, and roller speed. A central composite designwas used to optimize technological conditions. Under optimum conditions,the highest ω-3PUFA enrichment ratio (92.98%) was obtained atan evaporator temperature of 110.4 °C, a feeding rate of 78.7mL/h, a roller speed of 350 rpm, a feeding temperature of 80 °C,and an operating pressure 10 Pa. [ABSTRACT FROM AUTHOR]

Objective: To observe the effect of moxibustion on oxidative stress injury of nigrostriatal system in rats with Parkinson's disease (PD) based on nuclear factor erythroid 2-related factor (Nrf2)/antioxidant response element (ARE) pathway, and to explore its mechanism., Methods: A total of 48 SD rats were randomized into a blank group, a sham-operation group, a model group and a moxibustion group, 12 rats in each group. Unilateral two-point injection with 6-hydroxydopamine (6-OHDA) was adopted in the model group and the moxibustion group to establish the PD model; the operation manipulation in the sham-operation group was the same as the model group and the moxibustion group, and the same volume of 0.9% sodium chloride solutions was given by unilateral two-point injection. Moxibustion was adopted at "Baihui" (GV 20) and "Sishencong" (EX-HN 1) in the moxibustion group for 20 min, once a day, 6 times a week for 6 weeks. No intervention was given in the other 3 groups. Morphology of right mesencephalon substantia nigra was observed by HE staining, the expression of tyrosine hydroxylase (TH) in right mesencephalon substantia nigra was detected by immunohistochemistry method, the expression of reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), and glutathione peroxidase (GSH-Px) in corpus striatum was detected by colorimetry method, and the expression of Nrf2 and heme oxygenase-1 (HO-1) proteins was detected by Western blot in the 4 groups., Results: Clear tissue structure and complete dopaminergic neurons of right mesencephalon substantia nigra were observed in the blank group and the sham-operation group; unclear tissue structure, decreased and swelling dopaminergic neurons were observed in the model group; compared with the model group, more neurons were observed and the swelling of cyton was reduced in the moxibustion group. Compared with the sham-operation group, the expression of TH in right mesencephalon substantia nigra was decreased in the model group ( P <0.01); compared with the model group, the expression of TH in right mesencephalon substantia nigra was increased in the moxibustion group ( P <0.05). Compared with the sham-operation group, the expression of ROS, MDA was increased ( P <0.01), the expression of GSH, GSH-Px, Nrf2 and HO-1 was decreased in the model group ( P <0.01, P <0.05); compared with the model group, the expression of ROS, MDA was decreased ( P <0.05, P <0.01), the expression of GSH, GSH-Px, Nrf2 and HO-1 was increased in the moxibustion group ( P <0.05, P <0.01)., Conclusion: Moxibustion can alleviate oxidative stress injury of nigrostriatal system in rats with Parkinson's disease by activating the Nrf2/ARE pathway, and protect the dopamine neurons.