Green algae dominance quickly switches to cyanobacteria dominance after nutrient enrichment in greenhouse with high temperature

Xiaodong Wang,Xingguo Liu1,Boqiang Qin,Zhaojun Gu,Hao Xu,Hao Zhu,Guofeng Cheng,Huang Liu 한국생태학회 2015 Journal of Ecology and Environment Vol.38 No.3

In order to understand the mechanisms of conversion between different algal dominance, an experiment was performed in a greenhouse from 22 June to 10 July 2011. The experiment included a treatment group subjected to three instances of nutrient enrichment and a control with no nutrient enrichment. The initial water was dominated by Ankistrodesmus of Chlorophyta. The average water temperature at 08:30 h and 14:00 h during the experiment was 31.6°C and 34.6°C, respec¬tively. The results showed that the total nitrogen (TN), total phosphorus (TP), dissolved total nitrogen (DTN), dissolved total phosphorus (DTP), and soluble reactive phosphorus (SRP) concentrations in the treatment were significantly higher than in the control (P < 0.05). However, the TN/TP and DTN/DTP in the control was higher than in the treatment (P < 0.05). The dominant algae in the control did not change during the experiment, while the dominant algae in the treat¬ment switched to Planktothrix of Cyanophyta on day 9. The chlorophyll a (Chl-a), wet weight of all algae, wet weight of Cyanophyta, and percentage of Cyanophyta in the control were all significantly lower than in the treatment (P < 0.05). Amounts of zooplankton, especially rotifers, were present at the end of the experimental period. The density of rotifers between the control and treatment was not significantly different (P > 0.05), while the copepod density in the treatment was higher than in the control (P < 0.05). We conclude that green algae dominance quickly switches to cyanobacteria dominance after nutrient enrichment in a greenhouse with elevated temperature

Minimizing the Number of Transitions of 3D Printing Nozzles Using a Traveling-Salesman-Problem Optimization Model

Hao Liu,Rui Liu,Zhoupeng Liu,Shuhao Xu 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.9

In nozzle-based three-dimensional printing, transitions are movements of the printing nozzle from a path endpoint to a path start-point. These transitions diminish printing quality by causing strings. A method to minimize the number of transitions based on direction-parallel line segments is presented in this paper. The endpoints of line segments were considered to be “cities” in converting the problem of minimizing the number of transitions into a traveling salesman problem (TSP). A genetic algorithm solver was developed by designing an oriented mutation method for the TSP. Compared with other algorithms for solving the TSP, our algorithm generates paths with fewer transitions. The algorithm was tested using several fused-deposition-modeling and weld arc additive manufacture examples to confirm that the generated paths were reasonable.

Electronic effects on protective mechanism of electropolymerized coatings based on N-substituted aniline derivatives for mild steel in saline solution

Hao Liu,Baomin Fan,Zining Liu,Xiaoqi Zhao,Biao Yang,Xingwen Zheng,Hua Hao 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

Polyaniline (PANI), poly(N-methylaniline) (PNMA) and poly(N-formylanilide) (PNFA) coatings were fabricatedover mild steel via chronoamperometric strategy in oxalate electrolyte. Scanning electron microscope(SEM), attenuated total reflection infrared spectroscopy (ATR-IR) and X-ray photoelectronspectroscopy (XPS) evidenced the polymerization of monomers. Anticorrosive effects of PANI, PNMAand PNFA coatings for steel substrate were evaluated during long-term immersion in 3.5% NaCl solutionby potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and frequency modulation(EFM). Morphological variation for coated specimens before and after immersion in NaCl solutionwas also monitored by SEM and atomic force microscope (AFM). Differentiated protection capability wereobserved for three coatings following the sequence of PNFA > PNMA > PANI. Through electrochemical andinterfacial analyses, electroactivity and physical barrier were ascertained as the critical factors, especiallythe former one, in the long-term protection capacity. Electroactivity was distinguished by the elevatedapparent current density from non-destructive EFM measurements. Furthermore, electron-donationand -withdrawal effects of N-substituents played an essential role in coating electroactivity. In detail,N-substituents improved the anodic protection and physical barrier of PNMA and PNFA coatings. Particularly, formyl with electron-withdrawal effect reinforced the anodic protection and thus the superiorthe anticorrosion efficiency of PNFA for underlying steel.

Genome-wide DNA methylation profiling in differentiating Crohn’s disease from intestinal tuberculosis

Wu Hao,Liu Hongchun,Liu Haining,Chen Yanjie,Liu Taotao,Shen Xizhong,Liu Lili 한국유전학회 2022 Genes & Genomics Vol.44 No.5

Background: Differential diagnosis of Crohn's disease (CD) and intestinal tuberculosis (ITB) is still difficult in clinical pratice. DNA methylation has been considered as a favorable area for biomarker exploration and identification. Objective: The purpose of the current study was to evaluate DNA methylation changes between CD and ITB. Methods: We performed a genome-wide association study to identify differentially methylated positions (DMPs), including 8 CD patients (before the initial of biologics or immunomodulators), 6 ITB patients, and 8 healthy controls (HCs), in whole blood DNA using the Infinium HumanMethylation850 BeadChip. Results: Patients in the CD group and ITB group were all observed with hypo-methylated changes compared with HCs. However, the CD group overlaps with the ITB group in DNA methylation, suggesting a stable epigenetic profile between the two diseases. The pathway enrichment analysis showed the alternation in inflammation-related pathway, immune system, and signal transduction. Focused on the DMPs located in the promoter region, further analysis indicated hypermethylation of cg03122532 (5'UTR of KCNJ15) could be a potential CD-specific biomarker. Conclusions: We identified specific differential methylation loci related to CD and ITB in blood DNA. DNA metylation as a important epigenetic modification could contribute to the pathogenesis study and biomarker exploration of the diseases.

Control of thermoacoustic instability of liquid-spray flame with porous sound absorber

Hao Zhou,Hao Fang,Dongliang Wei,Zihua Liu,Zhaowen Wang,Hanxiao Meng 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.8

A kind of porous sound absorber was studied to control the thermoacoustic oscillation of liquid mist flame, which combined natural fibrous materials and perforated plate. It could optimize the sound absorption characteristics of fibrous materials by adding perforated plate and air cavity. The influences of the interlayer and back cavity depth of two kinds of fibrous materials with the mass of 20, 30, 40 g were investigated experimentally in an impedance tube and applied to control the oscillating ethanol flame. The results showed that the best depth of interlayer and back cavity were 20 cm and 30 cm, respectively. The addition of two kinds of fiber sandwich structures could reduce the amplitude of the sound pressure oscillation in the combustion chamber by 89.2 % and 92.6 %, as well as 88.0 % and 91.2 % in the plenum chamber, meanwhile, restrained the flame heat release fluctuation by 73 %. It was proved that the porous sound absorber could act as a damp in the acoustic transmission path and suppress the sound source.

Study on Influences and Elimination of Test Temperature on PDC Characteristic Spectroscopy of Oil-Paper Insulation System

Liu, Xiao,Liao, Ruijin,Lv, Yandong,Liu, Jiefeng,Gao, Jun,Hao, Jian The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Test temperature is an important factor affecting the measurement results of dielectric response of field power transformers. In order to better apply the polarization and depolarization current (PDC) to the condition monitoring of oil-paper insulation system in power transformers, the influences and elimination method of test temperature on PDC characteristic spectroscopy (PDC-CS) were investigated. Firstly, the experimental winding sample was measured by PDC method at different test temperatures, then the PDC-CS was obtained from the measurement results and its changing rules were discussed, which show that the PDC-CS appears a horizontal mobility with the rise of temperature. Based on the rules, the “time temperature shift technique” was introduced to eliminate the influence of test temperature. It is shown that the PDC-CS at different test temperatures can be converted to the same reference temperature coincident with each other.

Power Converters Based Advanced Experimental Platform for Integrated Study of Power and Controls

Liu, Wenxin,Kim, Jang-Mok,Wang, Cheng,Im, Won-Sang,Liu, Liming,Xu, Hao IEEE 2018 IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS - Vol.14 No.11

<P>With increasing interest in smart grid and renewable energy, significant investments have been allocated to promote related studies. Since there is a wide spectrum of topics to study, it is necessary to have an advanced experimental platform that can accommodate both system- and component-level studies, both hardware and algorithm designs, and both teaching and research. Unfortunately, such experimental platform is not commercially available. In this paper, an advanced power electronics based experimental platform is introduced. The system is consisted of one OPAL-RT real-time simulator, two one-bus microgrid testbeds, and two modular multilevel converters. The subsystems can form a multiple-bus microgrid testbed if connected through emulated power lines. The system can provide real-time simulation, controller hardware-in-the-loop (HIL) simulation, and power HIL simulation for power systems study. Various converter topologies can be configured with the modular converters for power electronics study. Both real-time simulator and DSP control boards can be used to implement advanced control algorithms. The designs and experiences shared in the paper will benefit many researchers that are in need of such system and promote power and energy related studies.</P>

Highly ordered mesoporous NiO anode material for lithium ion batteries with an excellent electrochemical performance

Liu, Hao,Wang, Guoxiu,Liu, Jian,Qiao, Shizhang,Ahn, Hyojun Royal Society of Chemistry 2011 Journal of materials chemistry Vol.21 No.9

<P>In this work, we have synthesized highly ordered mesoporous NiO materials by a nanocasting method using mesoporous silica KIT-6 as the hard templates. Mesoporous NiO particles were characterized by small angle X-ray diffraction (XRD), nitrogen adsorption/desorption, and transmission electron microscopy (TEM). The results demonstrated that the as-prepared mesoporous NiO had an ordered <I>Ia</I>3<I>d</I> symmetric mesostructure, with a high surface area of 96 m<SUP>2</SUP>/g. Mesoporous NiO materials were tested as an anode material for lithium ion batteries, exhibiting much lower activation energy (20.75 kJ mol<SUP>−1</SUP>) compared to the bulk NiO (45.02 kJ mol<SUP>−1</SUP>). We found that the mesoporous NiO electrode has higher lithium intercalation kinetics than its bulk counterpart. The specific capacity of mesoporous NiO after 50 cycles was maintained 680 mAh/g at 0.1 C, which was much higher than that of the commercial bulk NiO (188 mAh/g). Furthermore, at a high rate of 2C, the discharge capacity of mesoporous NiO was as high as 515 mAh/g, demonstrating the potential to be used for high power lithium ion batteries.</P> <P>Graphic Abstract</P><P>Ordered mesoporous NiO anode materials demonstrate high lithium intercalation kinetics and excellent electrochemical performance. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0jm03132a'> </P>

Black rice anthocyanidins prevent retinal photochemical damage via involvement of the AP-1/NF-κB/Caspase-1 pathway in Sprague-Dawley Rats

Hao Jia,Wei Chen,Xiuhua Wu,Shuai Li,Hong Liu,Jiru Liao,Weihua Liu,Mantian Mi,Longjian Liu,Daomei Cheng,Xiaoping Yu 대한수의학회 2013 Journal of Veterinary Science Vol.14 No.3

The effects of black rice anthocyanidins (BRACs) on retinal damage induced by photochemical stress are not well known. In the present study, Sprague-Dawley rats were fed AIN-93M for 1 week, after which 80 rats were randomly divided into two groups and treated with (n = 40) or without BRACs (n =40) for 15 days, respectively. After treatment, both groups were exposed to fluorescent light (3,000 ± 200 lux; 25oC), and the protective effect of dietary BRACs were evaluated afterwards. Our results showed that dietary BRACs effectively prevented retinal photochemical damage and inhibited the retinal cells apoptosis induced by fluorescent light (p < 0.05). Moreover, dietary BRACs inhibited expression of AP-1 (c-fos/c-jun subunits), up-regulated NF-κB (p65) expression and phosphorylation of IκB-α, and decreased Caspase-1 expression (p < 0.05). These results suggest that BRACs improve retinal damage produced by photochemical stress in rats via AP-1/NF-κB/Caspase-1apoptotic mechanisms.

An Experimental Investigation on the Characteristics of Automotive Air Spring

Hao Liu,Jaecheon Lee 한국자동차공학회 2008 한국자동차공학회 지부 학술대회 논문집 Vol.2008 No.11

In order to control air suspension system, the air spring characteristics, stiffness and effective area were experimentally researched through the static and dynamic tests. The displacement signal with large amplitude and low speed was executed on the air spring piston in the static test. Using test data, the static stiffness with different initial pressure and the effective area were obtained. It is found that the lowest value of the static stiffness is about 10KN/㎜ for various initial pressures and that the effective area is influenced more by the piston contour. In dynamic test the harmonic displacement signal with various frequencies was applied. The test results show that the hysteresis in one Force-Displacement cycle becomes better when excitation frequency increases, but does not change too much as the frequency is higher than 1㎐. And the dynamic stiffness goes up with increasing of the initial pressure and the excitation frequency.