Investigation on the Influence of Entrained Air to Internal Flow of Centrifugal Pumps under Cavitation Condition

Deng Fanjie,Yuan Jianping,Yang Song,Wang Biaobiao,Si Qiaorui 한국유체기계학회 2022 International journal of fluid machinery and syste Vol.15 No.1

The introduction of air is often used in engineering to delay the occurrence of cavitation. A steady simulation on a single-stage and single-suction centrifugal pump was used to study the influence of the air on the internal flow under cavitation condition at 1% inlet void fraction. Steady simulation based on SST k-ω turbulence model and Rayleigh-Plesset cavitation model included in Ansys CFX 17.0 were processed to obtain vapor volume fraction, gas volume fraction and the turbulent energy of the impeller under the condition of natural cavitation and cavitation with entrained air. A homogeneous two-phase flow model was adopted to describe the air-water mixed flow. The experimental cavitation performance curve provides boundary condition support for the numerical simulation. In conclusion, it shows that the head of the pump keeps steady after 1% air entrained like natural cavitation. Then it goes worse when the cavitation number decreases but with lower NPSHr which means cavitation performance is improved by 1% air entrained. It indicated that the entrained air changes the distribution of the vapor in the passage of the impeller. However, the descent of the pressure over a certain value will also do harm to the internal flow of the model pump whether it is ventilating or not. The internal flow of the pump will be seriously damaged and even be blocked completely due to more and more vapor generated causing a dramatic decline of the head.

Mg(OH)2/Graphene Nanocomposites Prepared by Cathodic Electrodeposition for the Adsorption of Congo Red

Xinzhong Deng,Yao-wu Wang,Jianping Peng,Kejia Liu,Nai-xiang Feng,Yuezhong Di 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.2

A facile cathodic electrodeposition process was developed to prepare Mg(OH)2/Graphene nanocomposites (MGN), which was used to remove Congo Red (CR), an anionic dye from aqueous solution. The morphology and phase structure were analyzed by transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman and X-ray photoelectron spectroscopy (XPS). The effects of experimental parameters, such as graphene content, adsorption time, initial concentrations of CR and pH values, on the adsorption capacity of CR were studied. The obtained MGN shows the good performance in CR, with an adsorption capacity of 1986.43 mg g-1. The equilibrium adsorption and kinetics data fit with Langmuir isotherm and the pseudo-second-order model, respectively. Thermodynamic data suggest that CR adsorption onto MGN is spontaneous (ΔG0 : –9.62 kJ mol-1 at 313 K, endothermic (ΔH0 : 36.261 kJ mol-1) and the degree of disorder increased (ΔS0 : 146.848 J moL-1 K-1) at the solidsolution interface. Moreover, the adsorption activation energy (Ea: 38.929 kJ mol-1) of CR evaluated from the Arrhenius equation illustrates that it is a physical process. This adsorbent exhibits efficient adsorption properties and high recycling efficiency, making it a promising adsorbent for removing anionic dyes.

A missense variant in NCF1 is associated with susceptibility to multiple autoimmune diseases

Zhao, Jian,Ma, Jianyang,Deng, Yun,Kelly, Jennifer A,Kim, Kwangwoo,Bang, So-Young,Lee, Hye-Soon,Li, Quan-Zhen,Wakeland, Edward K,Qiu, Rong,Liu, Mengru,Guo, Jianping,Li, Zhanguo,Tan, Wenfeng,Rasmussen, Nature Pub. Co 2017 Nature genetics Vol.49 No.3

<P>Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease with a strong genetic component characterized by autoantibody production and a type 1 interferon signatures. Here we report a missense variant (g.74779296G>A; p.Arg90His) in NCF1, encoding the p47phox subunit of the phagocyte NADPH oxidase (NOX2), as the putative underlying causal variant that drives a strong SLE-associated signal detected by the lmmunochip in the GTF2IRD1-GTF2I region at 7q11.23 with a complex genomic structure. We show that the p.Arg90His substitution, which is reported to cause reduced reactive oxygen species (ROS) production(2), predisposes to SLE (odds ratio (OR) = 3.47 in Asians (P-meta = 3.1 x 10(-104)), OR = 2.61 in European Americans, OR = 2.02 in African Americans) and other autoimmune diseases, including primary Sjogren's syndrome (OR = 2.45 in Chinese, OR = 2.35 in European Americans) and rheumatoid arthritis (OR = 1.65 in Koreans). Additionally, decreased and increased copy numbers of NCF1 predispose to and protect against SLE, respectively. Our data highlight the pathogenic role of reduced NOX2-derived ROS levels in autoimmune diseases.</P>

Preparation of Optically Active Poly(N-propargylamide) Gels and Their Application in Chiral Recognition

Dong Liu,Xiaoying Du,Jianping Deng,Wantai Yang 한국고분자학회 2011 Macromolecular Research Vol.19 No.7

Optically active gels based on helical N-propargylamide polymers were prepared using a one-pot twostep methodology: the pre-formation of helical N-propargylamide copolymer (defined as N=N-HP) and the preparation of gels bearing the helical copolymers. To prepare N=N-HP, N-propargylamide M1, which contained -N=Nfunctional group, and M2, which provided helical polymer chains for the resulting copolymers, underwent copolymerizations in the presence of (nbd)Rh^+B^-(C_6H_5)_4 as a catalyst. -N=N- groups in N=N-HP acted as an initiator to induce the free radical polymerization of styrene, yielding the designed gels. Trimethylol propane triacrylate (TMPTA) was used to improve the cross-linking degree of the gels. The obtained gels were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and circular dichroism (CD) spectroscopy measurements. The gels showed high optically activity, resulting from the helical structures of the N-propargylamide polymer chains. Preferential adsorption towards (R)-(+)-1-phenylethylamine in the two enantiomers was observed in the obtained gels, demonstrating the potentials of such gels in chiral recognition and chiral resolution.

Flexural behaviour of reinforced concrete beams strengthened with NSM CFRP prestressed prisms

Jiong-Feng Liang,Deng Yu,Shengjun Xie,Jianping Li 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.62 No.3

The behaviour of reinforced concrete beams strengthened with near surface mounted (NSM) CFRP prestressed prisms was experimentally investigated. Five RC beams were tested under four point bending. All beams were made with dimensions of 300 mm in width, 2000 mm in length and 150 in depth. The effects of presstress level of CFRP prestressed prisms and prism material type were studied. The failure mode, load capacity, deflection, CFRP strain, steel strain and ductility of the tested beams were all analyzed. The results showed that the behavior of the reinforced concrete beams strengthened with NSM CFRP prestressed prisms showed a significant increase in the load-carrying capacity and the deformation capacity. The NSM CFRP prestressed prisms strengthening technique could be considered as an effective method for repairing RC structures.

Integrated proteomic and metabolomic analyses reveal significant changes in chloroplasts and mitochondria of pepper (Capsicum annuum L.) during Sclerotium rolfsii infection

Liao Hongdong,Wen Xiangyu,Deng Xuelei,Wu Yonghong,Xu Jianping,Li Xin,Zhou Shudong,Li Xuefeng,Zhu Chunhui,Luo Feng,Ma Yanqing,Zheng Jingyuan 한국미생물학회 2022 The journal of microbiology Vol.60 No.5

Infection by Sclerotium rolfsii will cause serious disease and lead to significant economic losses in chili pepper. In this study, the response of pepper during S. rolfsii infection was explored by electron microscopy, physiological determination and integrated proteome and metabolome analyses. Our results showed that the stomata of pepper stems were important portals for S. rolfsii infection. The plant cell morphology was significantly changed at the time of the fungal hyphae just contacting (T1) or surrounding (T2) the pepper. The chlorophyll, carotenoid, and MDA contents and the activities of POD, SOD, and CAT were markedly upregulated at T1 and T2. Approximately 4129 proteins and 823 metabolites were clearly identified in proteome and metabolome analyses, respectively. A change in 396 proteins and 54 metabolites in pepper stem tissues was observed at T1 compared with 438 proteins and 53 metabolites at T2. The proteins and metabolites related to photosynthesis and antioxidant systems in chloroplasts and mitochondria were disproportionally affected by S. rolfsii infection, impacting carbohydrate and amino acid metabolism. This study provided new insights into the response mechanism in pepper stems during S. rolfsii infection, which can guide future work on fungal disease resistance breeding in pepper.

Association between Metabolic Syndrome and Microvascular Complications in Chinese Adults with Type 1 Diabetes Mellitus

Qianwen Huang,Daizhi Yang,Hongrong Deng,Hua Liang,Xueying Zheng,Jinhua Yan,Wen Xu,Xiangwen Liu,Bin Yao,Sihui Luo,Jianping Weng 대한당뇨병학회 2022 Diabetes and Metabolism Journal Vol.46 No.1

Background: Both type 1 diabetes mellitus (T1DM) and metabolic syndrome (MetS) are associated with an elevated risk of morbidity and mortality yet with increasing heterogeneity. This study primarily aimed to evaluate the prevalence of MetS among adult patients with T1DM in China and investigate its associated risk factors, and relationship with microvascular complications.Methods: We included adult patients who had been enrolled in the Guangdong T1DM Translational Medicine Study conducted from June 2010 to June 2015. MetS was defined according to the updated National Cholesterol Education Program criterion. Logistic regression models were used to estimate the odds ratio (OR) for the association between MetS and the risk of diabetic kidney disease (DKD) and diabetic retinopathy (DR).Results: Among the 569 eligible patients enrolled, the prevalence of MetS was 15.1%. While female gender, longer diabetes duration, higher body mass index, and glycosylated hemoglobin A1c (HbA1c) were risk factors associated with MetS (OR, 2.86, 1.04, 1.14, and 1.23, respectively), received nutrition therapy education was a protective factor (OR, 0.46). After adjustment for gender, age, diabetes duration, HbA1c, socioeconomic and lifestyle variables, MetS status was associated with an increased risk of DKD and DR (OR, 2.14 and 3.72, respectively; both P<0.05).Conclusion: Although the prevalence of MetS in adult patients with T1DM in China was relatively low, patients with MetS were more likely to have DKD and DR. A comprehensive management including lifestyle modification might reduce their risk of microvascular complications in adults with T1DM.

Heat-resistant Poly(methyl methacrylate) Modified by Biomass Syringaldehyde Derivative: Preparation, Thermostability and Transparency

Xiaobin Gao,Song Mei,Xueyong Yong,Danyu Zhao,Jinpeng Bao,Jianping Deng 한국섬유공학회 2019 Fibers and polymers Vol.20 No.11

Poly(methyl methacrylate) (PMMA) has found a lot of practical uses, however, how to efficiently and costeffectivelyimprove its relatively low thermal properties remains as an intractable academic challenge. This article reports anovel strategy for improving heat-resistance of PMMA by using biomass syringaldehyde. Syringaldehyde methacrylate(SMA) was first synthesized and then used as comonomer to copolymerize with methyl methacrylate (MMA) through bulkpolymerization and solution polymerization. The copolymers can be obtained in high yield and demonstrate remarkablyimproved heat-resistance according to differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) andderivative thermogravimetry analyses (DTG). Moreover, the modified PMMA still maintains good light transmittance invisible range. The study provides a new alternative for modifying PMMA, and the modified PMMA may find newapplications as heat-resistant polymeric material which cannot routinely achieved by PMMA itself. In addition, SMA as anew type of green heat-resistant modifier derived from renewable biomass syringaldehyde may have potential applications inheat-resistant modification of materials.

Dynamics of Microbial Community Structure, Function and Assembly Mechanism with Increasing Stand Age of Slash Pine (Pinus elliottii) Plantations in Houtian Sandy Area, South China

Zhang Xiaoyang,Xiong Si-Yi,Wu Xiukun,Zeng Bei-Bei,Mo Yang-Mei,Deng Zhi-Cheng,Wei Qi,Gao Yang,Cui Licao,Liu Jianping,Long Haozhi 한국미생물학회 2023 The journal of microbiology Vol.61 No.11

Establishing slash pine plantations is the primary method for restoring sandification land in the Houtian area of South China. However, the microbial variation pattern with increasing stand age remains unclear. In this study, we investigated microbial community structure and function in bare sandy land and four stand age gradients, exploring ecological processes that determine their assembly. We did not observe a significant increase in the absolute abundance of bacteria or fungi with stand age. Bacterial communities were dominated by Chloroflexi, Actinobacteria, Proteobacteria, and Acidobacteria; the relative abundance of Chloroflexi significantly declined while Proteobacteria and Acidobacteria significantly increased with stand age. Fungal communities showed succession at the genus level, with Pisolithus most abundant in soils of younger stands (1- and 6-year-old). Turnover of fungal communities was primarily driven by stochastic processes; both deterministic and stochastic processes influenced the assembly of bacterial communities, with the relative importance of stochastic processes gradually increasing with stand age. Bacterial and fungal communities showed the strongest correlation with the diameter at breast height, followed by soil available phosphorus and water content. Notably, there was a significant increase in the relative abundance of functional groups involved in nitrogen fixation and uptake as stand age increased. Overall, this study highlights the important effects of slash pine stand age on microbial communities in sandy lands and suggests attention to the nitrogen and phosphorus requirements of slash pine plantations in the later stages of sandy management.