Improvement of electric conductivity of LLDPE based nanocomposite by paraffin coating on exfoliated graphite nanoplatelets

Paraffin coated exfoliated graphite nanoplatelets (xGnP) reinforced with Linear Low-Density PolyEthylene (LLDPE) nanocomposites have been fabricated and characterized for mechanical, electrical and morphological properties. Paraffin was added to decrease the percolation threshold of electric conductivity. LLDPE–paraffin/xGnP nanocomposites were prepared by separate solution and total solution mixing methods. The mixture master batch of each mixing method was injection-molded to produce composites with a mini twin-screw extruder. The separate mixing method was not suitable since there was not enough electrical conductivity due to the low xGnP content in the nanocomposites. However, paraffin does not affect mechanical properties until around 30 wt% of content has been added, even though the content is low molecular weight polyethylene. When the total mixing method was used, the adding content of xGnP and paraffin was easily controlled. Five weight percentage of xGnP loaded nanocomposite showed electrical conductivity when 10 wt% of paraffin was added. From the results of SEM images of fracture surface and DSC, it could be seen that Paraffin was well coated on xGnP, resulting in a separate phase between xGnP and LLDPE. By coating paraffin on xGnP in the LLDPE matrix, the percolation threshold dramatically decreased compared to the xGnP–LLDPE nanocomposite.     

Flexible electronics: 12‐GHz Thin‐Film Transistors on Transferrable Silicon Nanomembranes for High‐Performance Flexible Electronics (Small 22/2010)

Multigigahertz flexible electronics are attractive and have broad applications. A gate‐after‐source/drain fabrication process using preselectively doped single‐crystal silicon nanomembranes (SiNM) is an effective approach to realizing high device speed. However, further downscaling this approach has become difficult in lithography alignment. In this full paper, a local alignment scheme in combination with more accurate SiNM transfer measures for minimizing alignment errors is reported. By realizing 1 μm channel alignment for the SiNMs on a soft plastic substrate, thin‐film transistors with a record speed of 12 GHz maximum oscillation frequency are demonstrated. These results indicate the great potential of properly processed SiNMs for high‐performance flexible electronics.     

Cholesterol Removal from Squid Liver Oil by Crosslinked β-Cyclodextrin

The present study was designed to optimize the different conditions for β-cyclodextrin (β-CD) crosslinked by adipic acid on cholesterol removal from squid liver oil. Different factors were concentrations of crosslinked β-CD, mixing temperature, ratio of squid liver oil to distilled water, mixing time and mixing speed. It was found that cholesterol removal from squid liver oil was significantly affected by concentrations of crosslinked β-CD, mixing temperature, ratio of squid liver oil to distilled water, mixing time and mixing speed. In a recycling study, cholesterol removal from the squid liver oil with recycled crosslinked β-CD in the first recycling trial was 81.05%, which was slightly lower than that with new crosslinked β-CD (87.06%). In up to three time trials, over 70% of cholesterol removal was observed. The present study indicated that the optimum conditions for cholesterol removal from squid liver oil using crosslinked β-CD were a 1:3 ratio of squid liver oil to distilled water, 25% (crosslinked β-CD/distilled water, w/v) crosslinked β-CD concentration, 20 min mixing time, 800 rpm mixing speed and 55 °C mixing temperature with about 87% cholesterol removal.     

Pathogenic microorganisms,heavy metals,and antibiotic residues in seven Korean freshwater aquaculture species

Food Science and Biotechnology - This survey was performed to estimate the levels of pathogenic microorganisms, antibiotic residues, and heavy metals in seven Korean freshwater aquaculture species...     

In vitro and in vivo anti-inflammatory activities of mixed fruit and vegetable juice

Food Science and Biotechnology - In this study, we attempted to develop fruit-based functional juice with anti-inflammatory activity for consumers living under heavy air pollution. At first, four...     

A breast modeler based on analysis of breast scans

The advent of 3D scanning technology has allowed effective measurement and analysis of breast size and shape, attracting interests by plastic surgeons, brassier designers, etc. Much work remains, however, before 3D scanning systems can be successfully used in automated analysis and synthesis of the breast—filtering noise, filling holes, and, in case a statistical analysis is desired, finding correspondence among each scan data. Moreover, analysis of a sagged breast is difficult to obtain, due to occlusions. In this paper, we address the problems and specific issues of using 3D scan data for the analysis and synthesis of breast models. The goal of our work is to build a breast modeler which can help both surgeons and garment designers in analyzing breast volume and surface measurements. Given enough samples of scanned breasts, our modeler can generate highly realistic breast shape, with some expected and consistent variability. Copyright © 2007 John Wiley & Sons, Ltd.     

Simulation of dynamics and control of a double-effect LiBr–H2O absorption chiller

A dynamic model has been developed to simulate dynamic operation of a real double-effect absorption chiller. Dynamic behavior of working fluids in main components was modeled in first-order nonlinear differential equations based on heat and mass balances. Mass transport mechanisms among the main components were modeled by valve throttling, ‘U’ tube overflow and solution sub-cooling. The nonlinear dynamic equations coupled with the subroutines to calculate thermodynamic properties of working fluids were solved by a numerical method. The dynamic performance of the model was compared with the test data of a commercial medium chiller. The model showed a good agreement with the test data except for the first 83 min during which different flow rates of the weak solution caused some discrepancy. It was found that the chiller dynamics is governed by the inlet temperatures of the cooling water and the chilled water when the heat input to the chiller is relatively constant. For a step change of load at constant inlet temperatures of the cooling water and the chilled water, the response time of the chilled water exit temperature was about 15 min and it was due to the thermal capacities of the chiller. The dilution cycle was found to be an essential means for improvement of control performance as well as anti-crystallization.     

Long term operation of high concentration powdered activated carbon membrane bio-reactor for advanced water treatment.

A pilot scale experiment was conducted to evaluate the performance of a membrane bioreactor filled with high concentration powdered activated carbon. This hybrid system has great potential to substitute for existing GAC or O3/BAC processes in the drinking water treatment train. The system was installed at a water treatment plant located downstream of the Nakdong river basin, Korea. Effluent of rapid sand filter was used as influent of the system which consists of PAC bio-reactor, submerged MF membrane module and air supply facility. PAC concentration of 20 g/L was maintained at the beginning of the experiment and it was increased to 40 g/L. The PAC has not been changed during the operational periods. The membrane was a hollow fiber type with pore sizes of 0.1 and 0.4 microm. It was apparent that the high PAC concentration could prevent membrane fouling. 40 g/L PAC was more effective to reduce the filtration resistance than 20 g/L. At the flux of 0.36 m/d, TMP was maintained less than 40 kPa for about 3 months by intermittent suction type operation (12 min suction/3 min idling). Adsorption was the dominant role to remove DOC at the initial operational period. However the biological effect was gradually increased after around 3 months operation. Constant DOC removal could be maintained at about 40% without any trouble and then a tremendous reduction of DBPs (HAA5 and THM) higher than 85% was achieved. Full nitrification was observed at the controlled influent ammonia nitrogen concentration of 3 and 7 mg/L. pH was an important parameter to keep stable ammonia oxidation. From almost two years of operation, it is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment under the recent situation of more stringent DBPs regulation in Korea.