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  • Author: Chuan Wang x
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Abstract

The electrohydrodynamic (EHD) flow induced by the corona discharge was experimentally investigated in an electrostatic precipitator (ESP). The ESP was a narrow horizontal Plexiglas box (1300 mm×60 mm×60 mm). The electrode set consisted of a single wire discharge electrode and two collecting aluminum plate electrodes. Particle Image Velocimetry (PIV) method was used to visualize the EHD flow characteristics inside the ESP seeded with fine oil droplets. The influence of applied voltage (from 8 kV to 10 kV) and primary gas flow (0.15 m/s, 0.2 m/s, 0.4 m/s) on the EHD flow transition was elucidated through experimental analysis. The formation and transition of typical EHD flows from onset to the fully developed were described and explained. Experimental results showed that the EHD flow patterns change depends on the gas velocity and applied voltage. EHD flow starts with flow streamlines near collecting plates bending towards the wire electrode, forming two void regions. An oscillating jet forming the downstream appeared and moved towards the wire electrode as voltage increased. For higher velocities (≥0.2 m/s), the EHD transition became near wire phenomenon with a jet-like flow structure near the wire, forming a void region behind the wire and expanding as voltage increased. Fully developed EHD secondary flow in the form of counter-rotating vortices appeared upstream with high applied voltage.

Abstract

The efficient reuse of homogeneous catalyst is important. Cation complex of [Ru(η6-p-cymene)(PPh3)(CH3CN) Cl]PF6 with different ligands was synthesized and characterized by infrared spectroscopy (IR), 1H-, 13C- and 31P-nuclear magnetic resonance spectroscopy (1H-, 13C- and 31P-NMR), element analysis (EA), and high resolution mass spectrometry (HR-MS). The complex was used as a catalyst for the hydrogen transfer reduction of carbonyl for the first time, presenting an excellent catalytic performance of 89%–98% conversion of acetophenone and its derivatives. The catalyst may be efficiently reused by the electro-adsorption of 10 times to one catalyst recovery. The cation [Ru] complex presented advantages of both homogeneous and heterogeneous catalysts.

Abstract

Accurate measurements of cigarette coal temperature are essential to understand the thermophysical and thermo-chemical processes in a burning cigarette. The last system-atic studies of cigarette burning temperature measurements were conducted in the mid-1970s. Contemporary cigarettes have evolved in design features and multiple standard machine-smoking regimes have also become available, hence there is a need to re-examine cigarette combustion. In this work, we performed systematic measurements on gas-phase temperature of burning cigarettes using an improved fine thermocouple technique. The effects of machine-smoking parameters (puff volume and puff duration) and filter ventilation levels were studied with high spatial and time resolutions during single puffs. The experimental results were presented in a number of differ-ent ways to highlight the dynamic and complex thermal processes inside a burning coal. A mathematical distribution equation was used to fit the experimental temperature data. Extracting and plotting the distribution parameters against puffing time revealed complex temperature profiles under different coal volume as a function of puffing intensities or filter ventilation levels. By dividing the coal volume prior to puffing into three temperature ranges (low-temperature from 200 to 400 °C, medium-temperature from 400 to 600 °C, and high-temperature volume above 600 °C) by following their development at different smoking regimes, useful mechanistic details were obtained. Finally, direct visualisation of the gas-phase temperature through detailed temperature and temperature gradient contour maps provided further insights into the complex thermo-physics of the burning coal. [Beitr. Tabakforsch. Int. 26 (2014) 191-203]

Abstract

A model is developed to describe the pressure dependence of the band gap energy for the dilute nitride GaNxAs1–x. It is found that the sublinear pressure dependence of E is due to the coupling interaction between E+ and E. We have also found that GaNxAs1−x needs much larger pressure than GaAs to realize the transition from direct to indirect band gap. It is due to two factors. One is the coupling interaction between the E+ and E. The other is that the energy difference between the X conduction band minimum (CBM) and the G CBM in GaNxAs1−x is larger than that in GaAs. In addition, we explain the phenomenon that the energy difference between the X CBM and the G CBM in GaNxAs1−x is larger than that in GaAs. It is due to the impurity-host interaction.

Abstract

Background: Visceral adipose tissue-derived serine protease inhibitor (vaspin) is a novel adipocytokine. Several studies have indicated that vaspin may exert an important role in the development of metabolic disorders.

Objective: Evaluate serum vaspin and its relation to clinical parameters in newly and previously diagnosed Chinese type 2 diabetes mellitus (T2DM) females as a case-control study.

Materials and methods: One hundred twenty female participants (newly and previously diagnosed T2DM patients) were recruited from an affiliated hospital of Harbin Medical University. Sixty healthy female volunteers from various communities were included as controls. Anthropometric parameters, serum fasting blood glucose, fasting insulin, lipid profile, HbA1c, and vaspin were measured in each participant.

Results: Serum vaspin levels were significantly lower in previously diagnosed T2DM patients (0.51±0.29 ng/mL) than in newly diagnosed T2DM patients (0.62±0.28 ng/mL) and healthy controls (0.69±0.31 ng/mL). However, there was no difference in serum vaspin between newly diagnosed T2DM patients and healthy controls. In multiple linear regression analysis, serum vaspin was significantly and positively associated with HbA1c in both newly and previously diagnosed T2DM patients, negatively associated with homeostasis model assessment of insulin resistance in previously diagnosed patients, and positively correlated with age and body mass index in healthy controls.

Conclusion: Serum vaspin was significantly lower in previously diagnosed T2DM patients than in newly diagnosed T2DM patients and healthy controls. Serum vaspin might be a predictor of poor glucose control and insulin resistance in T2DM.

Summary

To study the effects of tobacco rod circumference on cigarette combustion status, cigarettes were made with three different circumferences of 24 mm, 20 mm, 17 mm and otherwise identical construction. Their combustion characteristics, including combustion coal volume, characteristic temperature distribution, heating rate, instantaneous burn rate, and yields of selected mainstream smoke chemicals, were systematically measured. The results indicated that the cigarettes with the lowest circumference of 17 mm showed higher combustion temperatures with a smaller coal volume. The maximum instantaneous burn rate was distinctly different for the three cigarettes, from 1.84 mm/s to 2.48 mm/s, when their circumference was reduced from 24 mm to 17 mm. The tobacco mass consumption per puff showed a negative trend when the circumference decreased. The majority of the chemical compounds (16 of 21) measured in mainstream smoke decreased when the circumference was reduced, except for formaldehyde, while the yields of the chemical compounds produced per weight of cut tobacco, consumed during puffing, showed an obverse trend.

Objective To investigate the prevalence and levels of anti-HEV IgG in the population of Jiangsu Province.

Methods Total of 2 656 samples from Qindong and 11 463 samples from Anfeng were colleted. The anti- HEV antibody was qualitatively and quantitatively detected using ELISA kits and the references had been established.

Results The positive rates of anti-HEV IgG in male and female were 55.6% and 40.1%, respectively. The positive rate of anti-HEV IgM in male and female were both 3.4%. In opposite to anti-HEV IgG, the positive rate of anti-HEV IgM in Anfeng was significant higher than that in Qindong. The mean anti-HEV IgG titers for 6 age groups were 0.94, 0.92, 1.07, 1.46, 1.27, 1.19 and 0.68, 1.31, 1.08, 1.14, 1.31, 1.68 IU/ml, in Qindong and Anfeng region, respectively. The positive rate of anti-HEV IgG tended to increase with age and the titer of anti- HEV IgG was associated with age (R > 0.90).

Conclusions The results in this study showed that HEV was widely prevalent in both Qindong and Anfeng of Jiansu Province and the prevalence and the anti-HEV IgG titer were associated with gender and age.