Effects of Nano-Diamond on Magnetorheological Fluid Properties

Mingmei Zhao,Jinqiu Zhang,Jun Yao,Zhizhao Peng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.10

In order to analyze the effects of nano-diamond on the performance of magnetorheological fluids (MRFs), in this paper, the MRF-1 with a 2% mass fraction in nano-diamond and the MRF-2 without nano-diamond were prepared by the carbonyl iron powder as the dispersed phase and the synthetic mineral oil as the continuous phase. The viscosity and shear stress of MRFs under different magnetic fields were measured by the Anton-Paar rheometer (MCR 302). The MRF settling stability was studied by a standing observation method. A four-ball wear machine was utilized for the wear test at 0.1 T of magnetic field, whereas the magnetic field was provided by an external coil. Also, the three-dimensional white light interferometer was utilized to observe the surface of the ball wear spot, in order to determine the MRF friction properties. The results demonstrated that the nano-diamond had a significant increase in the surface wear. The shear yield strength and settling stability of the MRF could be highly enhanced. The higher the strength of the magnetic field was, the higher the difference in the shear yield strength was. These phenomena demonstrated that the physical properties of the nano-diamond could have a higher impact on MRF, which was of high significance to the preparation of MRFs with excellent performance.

Relationship between Molecular Structure Characteristics of Feed Proteins and Protein In vitro Digestibility and Solubility

Bai, Mingmei,Qin, Guixin,Sun, Zewei,Long, Guohui Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.8

The nutritional value of feed proteins and their utilization by livestock are related not only to the chemical composition but also to the structure of feed proteins, but few studies thus far have investigated the relationship between the structure of feed proteins and their solubility as well as digestibility in monogastric animals. To address this question we analyzed soybean meal, fish meal, corn distiller's dried grains with solubles, corn gluten meal, and feather meal by Fourier transform infrared (FTIR) spectroscopy to determine the protein molecular spectral band characteristics for amides I and II as well as ${\alpha}$-helices and ${\beta}$-sheets and their ratios. Protein solubility and in vitro digestibility were measured with the Kjeldahl method using 0.2% KOH solution and the pepsin-pancreatin two-step enzymatic method, respectively. We found that all measured spectral band intensities (height and area) of feed proteins were correlated with their the in vitro digestibility and solubility ($p{\leq}0.003$); moreover, the relatively quantitative amounts of ${\alpha}$-helices, random coils, and ${\alpha}$-helix to ${\beta}$-sheet ratio in protein secondary structures were positively correlated with protein in vitro digestibility and solubility ($p{\leq}0.004$). On the other hand, the percentage of ${\beta}$-sheet structures was negatively correlated with protein in vitro digestibility (p<0.001) and solubility (p = 0.002). These results demonstrate that the molecular structure characteristics of feed proteins are closely related to their in vitro digestibility at 28 h and solubility. Furthermore, the ${\alpha}$-helix-to-${\beta}$-sheet ratio can be used to predict the nutritional value of feed proteins.

Effects of alfalfa flavonoids on the production performance, immune system, and ruminal fermentation of dairy cows

Zhan, Jinshun,Liu, Mingmei,Su, Xiaoshuang,Zhan, Kang,Zhang, Chungang,Zhao, Guoqi Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.10

Objective: The objective of this study was to examine the effects of alfalfa flavonoids on the production performance, immunity, and ruminal fermentation of dairy cows. Methods: The experiments employed four primiparous Holstein cows fitted with ruminal cannulas, and used a $4{\times}4$ Latin square design. Cattle were fed total mixed ration supplemented with 0 (control group, Con), 20, 60, or 100 mg of alfalfa flavonoids extract (AFE) per kg of dairy cow body weight (BW). Results: The feed intake of the group receiving 60 mg/kg BW of AFE were significantly higher (p<0.05) than that of the group receiving 100 mg/kg BW. Milk yields and the fat, protein and lactose of milk were unaffected by AFE, while the total solids content of milk reduced (p = 0.05) linearly as AFE supplementation was increased. The somatic cell count of milk in group receiving 60 mg/kg BW of AFE was significantly lower (p<0.05) than that of the control group. Apparent total-tract digestibility of neutral detergent fiber and crude protein showed a tendency to increase (0.05<$p{\leq}0.10$) with ingestion of AFE. Methane dicarboxylic aldehyde concentration decreased (p = 0.03) linearly, whereas superoxide dismutase activity showed a tendency to increase (p = 0.10) quadratically, with increasing levels of AFE supplementation. The lymphocyte count and the proportion of lymphocytes decreased (p = 0.03) linearly, whereas the proportion of neutrophil granulocytes increased (p = 0.01) linearly with increasing levels of dietary AFE supplementation. The valeric acid/total volatile fatty acid (TVFA) ratio was increased (p = 0.01) linearly with increasing of the level of AFE supplementation, the other ruminal fermentation parameters were not affected by AFE supplementation. Relative levels of the rumen microbe Ruminococcus flavefaciens tended to decrease (p = 0.09) quadratically, whereas those of Butyrivibrio fibrisolvens showed a tendency to increase (p = 0.07) quadratically in response to AFE supplementation. Conclusion: The results of this study demonstrate that AFE supplementation can alter composition of milk, and may also have an increase tendency of nutrient digestion by regulating populations of microbes in the rumen, improve antioxidant properties by increasing antioxidant enzyme activities, and affect immunity by altering the proportions of lymphocyte and neutrophil granulocytes in dairy cows. The addition of 60 mg/kg BW of AFE to the diet of dairy cows was shown to be beneficial in this study.

Effects of alfalfa flavonoids extract on the microbial flora of dairy cow rumen

Zhan, Jinshun,Liu, Mingmei,Wu, Caixia,Su, Xiaoshuang,Zhan, Kang,Zhao, Guo qi Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.9

Objective: The effect of flavonoids from alfalfa on the microbial flora was determined using molecular techniques of 16S ribosome deoxyribonucleic acid (rDNA) analysis. Methods: Four primiparous Holstein heifers fitted with ruminal cannulas were used in a $4{\times}4$ Latin square design and fed a total mixed ration to which alfalfa flavonoids extract (AFE) was added at the rates of 0 (A, control), 20 (B), 60 (C), or 100 (D) mg per kg of heifer BW. Results: The number of operational taxonomic units in heifers given higher levels of flavonoid extract (C and D) was higher than for the two other treatments. The Shannon, Ace, and Chao indices for treatment C were significantly higher than for the other treatments (p<0.05). The number of phyla and genera increased linearly with increasing dietary supplementation of AFE (p<0.05). The principal co-ordinates analysis plot showed substantial differences in the microbial flora for the four treatments. The microbial flora in treatment A was similar to that in B, C, and D were similar by the weighted analysis. The richness of Tenericutes at the phylum level tended to increase with increasing AFE (p = 0.10). The proportion of Euryarchaeota at the phylum level increased linearly, whereas the proportion of Fusobacteria decreased linearly with increasing AFE supplementation (p = 0.04). The percentage of Mogibacterium, Pyramidobacter, and Asteroleplasma at the genus level decreased linearly with increasing AFE (p<0.05). The abundance of Spirochaeta, Succinivibrio, and Suttonella at the genus level tended to decrease linearly with increasing AFE (0.05<p<0.10). Conclusion: Including AFE in the diet of dairy cows may alter the microbial composition of the rumen; however its effect on nutrient digestibility remains to be determined.

A high-resolution timescale for the Miocene Shanwang diatomaceous shale lagerstätte (China): development of Wavelet Scale Series Analysis for cyclostratigraphy

Jifeng Yu,Xinlong Pang,Wenzhao Fu,Jason Hilton,Mingmei Liang,Zongkai Jiang,Xiuli Zhao,Wenyan Qiao,Suo Shi,Diandong Zhang,Huitao Cao,Haibo Jia,Yadong Wang,Xiaoke Hu,Rui Zhang 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.5

The Miocene aged Shanwang Formation from the Shanwang National Geopark in China represents a succession of lacustrine diatomaceous shales containing an abundant and diverse biota with lagerstätte fossilization of soft tissues. To date, the Shanwang Formation has not been investigated for cyclostratigraphy nor has it been dated with high precision methods. Now we use thorium data as a paleoenvironmental and paleoclimatic proxy to conduct a detailed cyclostratigraphic analysis. A new and simple cyclostratigraphic method, Wavelet Scale Series Analysis (WSSA) is developed to recognize Milankovitch cycles. A total of three short eccentricity and fifteen precession cycles are identified; obliquity cycles are not apparent. In the sedimentary succession, the corresponding precession and short eccentricity cycles are 1.17 m and 4.98 m thick respectively, with this verified by Correlation Coefficient (COCO) analysis and Multitaper-Method (MTM) spectral analysis. We estimate the studied interval was deposited over a duration of 0.3 Myr with a depositional rate of c. 5.7 cm/kyr. Paleomagnetic and radio isotope dating data shows that the diatomaceous shale was deposited during Chron C5En, which places it at approximately 18.5 Ma during the Burdigalian stage of the Early Miocene, rather than in the Middle Miocene as previously thought. The Shanwang lagerstätte biota therefore predates the Middle Miocene Climate Optimum (MMCO) and did not form within it. The geological time scale with a high resolution of 20 kyr was set accordingly.