Dynamic Rheological Studies of Poly(p-phenyleneterephthalamide) and Carbon Nanotube Blends in Sulfuric Acid

We have studied the dynamic scanning of liquid-crystalline (LC) poly(p-phenyleneterephthalamide) sulfuric acid (PPTA-H2SO4) solution, and its blend with single-walled carbon nanotubes (SWNTs), by using a flat plate rotational rheometer. The effects of weight concentration and molecular weight of PPTA, as well as operating temperature, on dynamic viscoelasticity of the PPTA-H2SO4 LC solution system are discussed. The transition from a biphasic system to a single-phase LC occurs in the weight concentration range of SWNTs from 0.1% to 0.2%, in which complex viscosity reaches the maximum at 0.2 wt% and the minimum at 0.1 wt%, respectively, of SWNTs. With increasing SWNT weight concentration, the endothermic peak temperature increases from 73.6 to 79.9 °C. The PPTA/SWNT/H2SO4 solution is in its plateau zone and storage modulus (G′) is a dominant factor within the frequency (ω) range of 0.1–10 rad/s. As ω increases, the G′ rises slightly, in direct proportion to the ω. The loss modulus (G″) does not rise as a function of ω when ω < 1 s−1, then when ω > 1 s−1 G″ increases faster than G′, yet not in any proportion to the ω

The influence of insecure attachment on undergraduates’ jealousy: the mediating effect of self-differentiation

BackgroundJealousy is a complex emotion and can be healthy or pathological, depending on the intensity and the degree of control. Excessive jealousy was characterized by anxiety, anger, and alienation in the insecure attachment relationship.ObjectiveTo explore how insecure attachment triggered this intense emotion, this study investigated the relationship between two insecure attachment dimensions and jealousy and explored the influence of self-differentiation on the relationship.MethodA total of 477 undergraduates participated in the study, and the Bringle self–report jealousy scale (BSJS), the relationship questionnaire (RQ), the intimate relationship experience questionnaire (ECR), and the revised edition of self–the differentiation questionnaire (DSR) were used.ResultThe results showed that: (1) attachment anxiety had a significant positive predictive effect on jealousy, but attachment avoidance had no significant positive predictive effect; (2) self-differentiation partially mediated the relationship between attachment anxiety and jealousy, but it has no significant mediating effect between attachment avoidance and jealousy.ConclusionThe results suggest that attachment anxiety was correlated with jealousy because it strengthened the intensity of anxiety and anger toward their attachment figures and became out of control through a lower level of self-differentiation, which has important implications for clinical intervention

Isolation of four diatom strains from tidal mud toward biofuel production

Conference Name:2012 International Conference on Biomedical Engineering and Biotechnology, iCBEB 2012. Conference Address: Macau, China. Time:May 28, 2012 - May 30, 2012.Development and utilization of bio-energy is an important way to relieve the pressure of global energy shortage. Biodiesel can be a focus of the bio-energy, because it is a cleaner-burning and renewable fuel. Micro algae have been considered to be an ideal source of biodiesel for its high growth rate and high lipid content. Benthic diatoms in tidal mud are considered to be new candidate for obtaining high lipid content micro algal strains although they have not been well noticed. The purpose of this study is getting the diatom strains with high-lipid content from tidal mud toward biofuel production. With microtubule method, four diatom strains were successfully isolated from the tidal mud located in Haicang, Xiamen. They are Navicula halophila, Nitzschia frustulum var. symbiotica, Amphora coffeaeformis, and Nitzschia closterium. The characteristics of morphology, ecology, and distribution of each species are described in the present paper with images of light microscope and electron microscope. Diatoms were cultured in the laboratory and the lipid content of each strain was determined. The lipid content (% dried weight) of the four diatoms are: Navicula halophila 39.1%, Nitzschia frustulum var. symbiotica 35.7%, Amphora coffeaeformis 26.1%, and Nitzschia closterium 18.9%. The result indicates that the lipid content of diatoms from tidal mud is relatively higher compared to the strains from seawater which can be a good source candidate of micro algal biodiesel. 漏 2012 IEEE

Continuous high-temperature fluidized bed pyrolysis of coal in complex atmospheres: Product distribution and pyrolysis gas

This study is devoted to investigating the continuous coal pyrolysis in a laboratory fluidized bed reactor that fed coal and discharged char continuously at temperatures of 750-980 degrees C and in N-2-base atmospheres containing O-2, H-2, CO, CH4 and CO2 at varied contents. The results showed that the designed continuous pyrolysis test provided a clear understanding of the coal pyrolysis behavior in various complex atmospheres free of and with O-2. The effect of adding H-2, CO, CH4 or CO2 into the atmosphere on the tar yield was related to the O-2 content in the atmosphere. Without O-2 in the atmosphere, adding H-2 and CO2 decreased the pyrolysis tar yield, but the tar yield was conversely higher with raising the CO and CH4 contents in the atmosphere. In O-2-containing atmospheres, the influence from varying the atmospheric gas composition on the product distribution and pyrolysis gas composition was closely related to the oxidation or gasification reactions occurring to char, tar and the tested gas. (C) 2012 Elsevier B.V. All rights reserved

Ion fluxes Involved in the Adaptation of the Estuarine Diatom <i>Coscinodiscus centralis</i> Ehrenberg to Salinity Stress

Although estuarine diatoms have a wide range of salt tolerance, they are often severely stressed by elevated salt concentrations. It remains poorly understood how estuarine diatoms maintain ionic homeostasis under high-salinity conditions. Using a scanning ion-selective electrode technique, this study determined the fluxes of H+, Na+, and K+ involved in the acclimatization of the estuarine diatom Coscinodiscus centralis Ehrenberg after an elevation in salinity from 15 psu to 35 psu. The C. centralis cells exhibited marked H+ effluxes after a transient treatment (TT, 30 min) and short-term treatment (ST, 24 h). However, a drastic shift of H+ efflux toward an influx was induced in the long-term treatment (LT, 10 days). The Na+ flux under TT, ST, and LT salinity conditions was found to accelerate the Na+ efflux. More pronounced effects were observed under the ST and LT salinity conditions compared to the TT salinity condition. The K+ influx showed a significant increase under the LT salinity condition. However, the salinity-induced Na+/H+ exchange in the estuarine diatom was inhibited by amiloride and sodium orthovanadate. These results indicate that the Na+ extrusion in salt-stressed cells is mainly the result of an active Na+/H+ antiport across the plasma membrane. The pattern of ion fluxes under the TT and ST salinity conditions were different from those under the LT salinity conditions, suggesting an incomplete regulation of the acclimation process in the estuarine diatom under short-term salinity stress