5,155 research outputs found

    Characterizations on microencapsulated sunflower oil as self-healing agent using In situ polymerization method

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    This paper emphasizes the characterization on the microencapsulation of sunflower oil as self-healing agent. In-situ polymerization method mainly implicates in the microencapsulation process. The analysis of microencapsulated sunflower oil via prominent characterization of yield of microcapsules, microcapsules characteristics and Fourier Transmission Infa-Red Spectroscopy (FTIR). The prime optimization used was reaction time of microencapsulation process in the ranges of 2, 3 and 4 h. The higher reaction time of microencapsulation process resulted in a higher yield of microcapsules. The yield of microcapsules increases from 46 to 53% respectively by the increasing of reaction time from 2 to 4 h. The surface morphology study associating the diameter of microcapsules measured to analyse the prepared microcapsules. It was indicated that microcapsules were round in shape with smooth micro-surfaces. It was discovered that the diameter of microcapsules during microencapsulation process after 4 h reaction time was in average of 70.53 μm. This size was measured before filtering the microcapsules with solvent and dried in vacuum oven. Apparently, after filtering and drying stage, the diameter of microcapsules specifically identified under Field Emission Scanning Electron Microscopy (FESEM) showing the size of 2.33 μm may be due to the removing the suspended oil surrounded the microcapsules. Sunflower oil as core content and urea formaldehyde (UF) as shell of microcapsules demonstrated the proven chemical properties on characterization by FTIR with the stretching peak of 1537.99 - 1538.90 cm-1 (-H in -CH2), 1235.49 - 1238.77 cm-1 (C-O-C Vibrations at Ester) and 1017.65 - 1034.11 cm-1 (C-OH Stretching Vibrations). It was showed that sunflower oil can be considered as an alternative nature resource for self-healing agent in microencapsulation process. The characterization of microencapsulated sunflower oil using in-situ polymerization method showed that sunflower oil was viable self-healing agent to be encapsulated and incorporated in metal coating

    Time perspective, depression, and substance misuse among the homeless

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    Using the Zimbardo Time Perspective Inventory (ZTPI; P. G. Zimbardo & J. N. Boyd, 1999), the authors found that homeless people, in comparison with a control group, had a significantly more negative outlook concerning their past and present as evinced by high Past-Negative and Present-Fatalistic scores and low Past-Positive scores on the ZTPI. However, the homeless individuals were almost indistinguishable from control participants on measures of Present-Hedonism and Future thinking. The homeless individuals had significantly higher levels of depression, with 31 out of 50 (62%) reaching criteria for probable depression. However, this finding was unrelated to their atypical time perspective. There was no significant relation between substance misuse and time perspective. Despite their current difficulties, including depression and drug abuse, the homeless individuals maintained a propensity toward future thinking characterized by striving to achieve their goals.

    Antimicrobial activities of marine fungi from Malaysia

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    Copyright 2011 Elsevier B.V., All rights reserved.Peer reviewedPublisher PD

    Nano-electromechanical Zero-dimensional Freestanding Nanogap Actuator

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    Micromachined free standing nanogap with metal electrodes is presented. The gap size is as small as 17 nm, and can be reduced further with electrostatic or piezoelectric actuation. The nanoscale gap is fabricated by industrial standard optical lithography and anisotropic wet chemical Si etching. Electron transport between the metal electrodes with optical stimulus enhancing photon-electron coupling (plasmon) is presented

    Laser collimation of an atomic gallium beam

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    The linear-perpendicular-linear polarization gradient technique was used for investigating laser collimation of a gallium atomic beam in one dimension. The full angular divergence of the atomic beam was reduced to 0.3 mrad by operating on a particular electron transition at 294.45 nm. The transverse velocity of the atoms was reduced to 11 cm/s, which was about half of the Doppler cooling limit. The one-dimensional kinetic energy of atoms was reduced to 6 neV. The transition state exhibited optical pumping of the atoms by the cooling laser

    Measurement of the hyperfine structure of the 4d2D 3/2,5/2 levels and isotope shifts of the 4p2p 3/2 ? 4d2D3/2 and 4p2p 3/2 ? 4d2D5/2 transitions in gallium 69 and 71

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    The hyperfine structure of the 4d2D3/2,5/2 levels of 69,71Ga is determined. The 4p2P3/2 ? 4d2D3/2 (294.50-nm) and 4p2P3/2 ? 4d2D5/2 (294.45-nm) transitions are studied by laser-induced fluorescence in an atomic Ga beam. The hyperfine A constant measured for the 4d2D5/2 level is 77.3 ± 0.9 MHz for 69Ga and 97.9 ± 0.7 MHz for 71Ga (3s errors). The A constant measured for the 4d2D3/2 level is -36.3 ± 2.2 MHz for 69Ga and -46.2 ± 3.8 MHz for 71Ga. These measurements correct sign errors in the previous determination of these constants. For 69Ga the hyperfine B constants measured for the 4d2D5/2 and the 4d2D 3/2 levels are 5.3 ± 4.1 MHz and 4.6 ± 4.2 MHz, respectively. The isotope shift is determined to be 114 ± 8 MHz for the 4p2P3/2 ? 4d2D3/2 transition and 115 ± 7 MHz for the 4p2P3/2 ± 4d 2D5/2 transition. The lines of 71Ga are shifted to the blue. This is in agreement with previous measurement
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