Engineering topics

Wang, Lun

Publications and source records attributed to Wang, Lun.

5 records

DOE OSTI2019

A new triterpene diglycoside from the roots of Bupleurum chinense DC. and its inhibitory effect on adipogensis in 3T3-L1 cells

A new triterpene diglycoside, tibesaikosaponin V (TKV), was isolated from the methanol extract of the roots of Bupleurum chinense DC. by normal and reversed phase column chromatography. The chemical structure of this new compound was elucidated based on extensive spectroscopic analysis, including 1D and 2D NMR, HR-ESI-MS, and chemical degradation method. Our results indicated that TKV inhibited lipid accumulation and triacylglycerol content occurred without cytotoxicity to 3T3-L1 adipocytes. Furthermore, TKV significantly suppressed the mRNA expression of nuclear transcription factors such as, peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα). These results suggest that TKV shows the ability to inhibit 3T3-L1 preadipocyte differentiation of and may have therapeutic potential for obesity and its associated metabolic disorders.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2018

Long noncoding RNA H19-derived miR-675 aggravates restenosis by targeting PTEN

Highlights: • LncRNA H19 and miR-675 are positively correlated with restenosis. • LncRNA H19 promotes VSMCs proliferation. • LncRNA H19-derived miR-675 directly targets on PTEN. • LncRNA H19 aggravates restenosis in a miR-675-dependent manner. Restenosis is mainly attributed to excessive proliferation of vascular smooth muscle cells (VSMCs). Noncoding RNAs have been identified as key regulators of diverse pathological processes. We reported that the long noncoding RNA H19 (LncRNA H19) and LncRNA H19-derived microRNA (miR-675) are overexpressed in neointima of balloon-injured artery. Thus, the present study aims to evaluate the role of LncRNA H19 on VSMCs proliferation. To determine the changes of LncRNA H19 and miR-675 expression in the injured arterial wall, the standard rat carotid artery balloon injury model was used. In vivo studies demonstrated that both LncRNA H19 and miR-675 were upregulated after vascular injury. Correlation analysis revealed a positive relationship between LncRNA H19/miR-675 and the ratio of intima to media. Gain-of-function studies showed that the overexpression of LncRNA H19 accelerated T/G HA-VSMC proliferation in vitro. We further validated that PTEN is the target gene of miR-675 as demonstrated by luciferase assay. Finally, the results of the rescue experiment indicated that LncRNA H19 promoted the proliferation of T/G HA-VSMC in a miR-675-dependent manner. This finding not only reveal a novel function of LncRNA H19, but also has important diagnostic and therapeutic implications in the setting of restenosis and perhaps other vascular proliferative disorders as well.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2013

A new strategy to diminish the 4 V voltage plateau of LiNi{sub 0.5}Mn{sub 1.5}O{sub 4}

Graphical abstract: The annealed sample LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} cannot eliminate the 4-V voltage plateau completely. The Mg-doped compound LiNi{sub 0.5}Mn{sub 1.45}Mg{sub 0.05}O{sub 4} can effectively diminish the 4 V voltage plateau during charge and discharge process. - Highlights: • Mg-doped compound LiNi{sub 0.5}Mn{sub 1.45}Mg{sub 0.05}O{sub 4} was prepared. • The 4 V voltage plateau in the charge–discharge curves of LiNi{sub 0.5}Mn{sub 1.45}Mg{sub 0.05}O{sub 4} was diminished. • Compound LiNi{sub 0.5}Mn{sub 1.45}Mg{sub 0.05}O{sub 4} exhibited good electrochemical properties. - Abstract: As for spinel LiNi{sub 0.5}Mn{sub 1.5}O{sub 4}, there is 4 V voltage plateau in the charge–discharge profiles. This voltage plateau can be reduced by an annealing process, however it is hard to avoid it completely. In this study, a new strategy of partial substitution for Mn by Mg is applied. There is no 4 V voltage plateau in the charge–discharge profiles of Mg-doped compound LiNi{sub 0.5}Mn{sub 1.45}Mg{sub 0.05}O{sub 4}. This compound exhibits good electrochemical properties which can be used as cathode material of lithium ion batteries. At 1 C rate, it can deliver a capacity of around 129 mAh g{sup −1} and remain good cycle performance.

36 MATERIALS SCIENCE↗

DOE OSTI2012

Oxy-Combustion Boiler Material Development

Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year) data. The test program details and data are presented herein.

36 MATERIALS SCIENCE↗

DOE OSTI2012

Oxy-Combustion Boiler Material Development

Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO 2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year) data. The test program details and data are presented herein.

20 FOSSIL-FUELED POWER PLANTS↗