NapWell: An EOG-based Sleep Assistant Exploring the Effects of Virtual Reality on Sleep Onset

Virtual Reality - We present NapWell, a Sleep Assistant using virtual reality (VR) to decrease sleep onset latency by providing a realistic imagery distraction prior to sleep onset. Our proposed...     

Stagemix video generation using face and body keypoints detection

Multimedia Tools and Applications - Playing multiple stage videos of a particular singer as if they are one is called Stagemix video. The consumption of video media has increased recently, and the...     

Studies on melt spinning. VII. Elongational viscosity and fiber morphology of multiphase polymer systems

Melt spinning experiments were carried out to investigate the elongational behavior and fiber morphology of multiphase polymer systems. Materials chosen for study were blends of calcium carbonate-filled polypropylene with general-purpose polystyrene and blends of calcium carbonate-filled polypropylene with high-impact polystyrene. The former is a three-phase system in which the CaCO₃ particles are dispersed, and the latter is a four-phase system in which CaCO₃ particles are dispersed, together with rubbery butadiene particles. Note that polypropylene is incompatible with the matrix of high-impact polystyrene. The experimental technique described in part I of this series was used to determine the elongational viscosity. With the four-phase system, the apparent elongational viscosity tends to increase as the stretch ratio is increased above a certain critical value which appears to be ca. 25. This transition does not occur with the three-phase system and is attributable to elongation of the suspended rubber particles. The addition of small amounts of HIPS to PP-CaCO₃ increases spinnability in general, whereas larger amounts decrease spinnability.     

Surface characterization of 8‐quinolinyl acrylate‐grafted poly(ethylene terephthalate) prepared by plasma glow discharge and it's antibacterial activity

Poly(ethylene terephthalate) (PET) film was exposed to oxygen plasma glow discharge to produce peroxides on its surface. These peroxides were then used as catalysts for the polymerization of 8‐quinolinyl acrylate (QA) to prepare the PET grafted with QA (PET‐Q). The surface‐modified PET was characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR) and X‐ray photoelectron spectroscopy (XPS). The introduction of QA to the PET surface was confirmed by observing the presence of nitrogen in the XPS survey scan and high‐resolution spectra. The amount of QA grafted on to the PET surface as measured by the gravimetric method was about 5.2 μg cm^?2. The antibacterial activity of the surface‐modified PET texture was investigated by using a shake‐flask and an inhibition zone test method. After 6 h of shaking, the PET grafted with QA showed the inhibition (91%) of the growth of the gram‐positive microorganism, S. aureus. Even after laundering ten times, an effectiveness of the inhibition was found. However, little inhibition was shown with the gram‐negative microorganism, K. pneumoniae. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 863–868, 2006     

Effects of Temperature and Reagent Concentration on the Morphology of Chemically Vapor Deposited β-Ta2O5

Crystalline β-Ta₂O₅ coatings were deposited on hot-isostatically-pressed Si₃N₄ by reacting TaCl₅ with H₂ and CO₂ in the temperature range of 1000°–1300°C and at a pressure of 660 Pa. The Ta₂O₅ coatings generally consisted of wellcoalesced 2–3 μm grains, resulting in the formation of a nonporous coating morphology. However, the presence of microcracks on the as-deposited surface was consistently observed. The surface morphology, texture, and growth rate of the coatings were examined as a function of deposition parameters.     

Comonomer enhancement effect of 1-hexene in ethylene copolymerization catalyzed over MgCl2/THF/TiCl4 catalysts

Homo- and copolymerization of ethylene were performed by using a catalyst system composed of TiCl₄/THF/MgCl₂ complex activated with AlEt₃ at 70°C and 3 atm. To investigate the effect of the compositional difference of the catalyst on the rates of homo- and copolymerization and on the reactivity in ethylene–hexene copolymerization, a series of six catalysts with different compositions (Mg/Ti = 0.4–16.5) were prepared by coprecipitation. The catalytic activity in ethylene polymerization increased sharply with the Mg/Ti ratio from 21 (Mg/Ti = 0.4) to 1477 kg PE/g-Ti h (Mg/Ti = 16.5). The activity in copolymerization with 1-hexene also increased with Mg/Ti ratio. The values of r₁ were 120, regardless of Mg/Ti ratios within the experimental error range. Enhancement of the polymerization rate by the addition of 1-hexene in the reaction medium was observed only for the catalysts of low Mg/Ti ratio. This unusual effect of 1-hexene on the polymerization rate was explained by chemical and physical processes that occurred during polymerization. © 1993 John Wiley & Sons, Inc.     

Effect of temperature, oxidant and catalyst loading on the performance of direct formic acid fuel cell

We investigated the effect of temperature, oxidant and catalyst loading on the performance of direct formic acid fuel cell (DFAFC). When oxidant was changed from air to oxygen, the power density was increased to 17.3 mW/ cm² at 25 ‡C. The power density of DFAFC operated with oxygen showed a maximum value of 40.04 mW/cm² with the temperature rise from room temperature to 70 °C. The highest power density of DFAFC using air was observed for Pt-Ru black catalyst with loading of 8 mgPt/cm² at room temperature. At 70 ‡C; however, the performance of catalyst with the loading of 4 mgPt/cm² was higher than that of 8 mgPt/cm². The DFAFC, operated with oxygen and catalyst of 4 mgPt/cm² loading, showed the best performance at all temperature range. The enhancement of cell performance with an increase of catalyst loading is believed to come from an increase of catalyst active sites. However, operated at higher temperature or with oxygen, the cell with higher catalyst loading showed lower performance than expected. It is speculated that the thick catalyst layer inhibits the proton transport.     

Simultaneous Chemical Vapor Deposition of Boron Nitride and Aluminum Nitride

Two chemically different phases, hexagonal BN and AIN, were simultaneously produced by chemical vapor deposition (CVD) using an impinging jet reactor and the BCl₃─AlCl₃─NH₃─Ar reagent system. The microstructure of the BN + AIN composite coatings was strongly dependent on temperature, pressure, and BCl₃ and AlCl₃ concentrations. The growth characteristics of BN and AIN in the codeposition system were similar to those expected from the single-phase deposition processes (i.e., BN-CVD and AIN-CVD), except the growth of AIN whiskers was accentuated, and competition between BN and AIN deposition in the composites was suspected to be the cause of less-crystalline deposits. In both BN + AIN-CVD and AIN-CVD, the growth of AIN whiskers became more apparent with increasing pressure or temperature. The codeposition behavior observed experimentally was compared with thermodynamic predictions.     

Dissolution and wet spinning of silk fibroin using phosphoric acid/formic acid mixture solvent system

Regenerated silk fibroin (SF) filaments could be prepared by wet spinning in common solvent/coagulation system. SF was directly dissolved in mixture solvent of phosphoric acid and formic acid (20/80–30/70 ratio) and coagulated in methanol bath. The concentration and stability of SF dope solution have been studied by varying the mixture ratios of these solvents in accordance with elucidating the role of formic acid in the mixture solvent system. Morphological structure as well as crystalline structure of the regenerated filament was examined using SEM and XRD analyses. As a result of tensile test, the regenerated SF filament, which was made by one‐step dissolution and coagulation process, had good mechanical properties, 2.3 gf/d tenacity and 18% breaking strain. In this study, a simple wet spinning method which enables to apply to practical production has been reported for the preparation of the regenerated SF filament. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis of needle‐like polyanilines

Needle‐like polyanilines were prepared in aqueous media by chemical oxidation. p‐Toluenesulfonic acid (pTSA) was used to protonate aniline (ANi) and readily made the anilinium complex. By slowly adding ammonium peroxydisulfate (APS) at 15°C, polyanilines were prepared in the micelles and grew to be needle‐like aggregates potentially useful as conductive fillers for electromagnetic interference shielding and radar‐absorbing materials. The needle‐like aggregates of protonated polyaniline prepared at 15°C and 0.5 M aniline concentration with 3 h of APS addition time showed conductivity up to 3 S/cm and a maximum aspect ratio of 26 L/D. They were observed by scanning electron microscopy to peel off partially into fibrils after washing. The needle‐like polyaniline‐pTSA complexes prepared with 0.5 M aniline concentration showed good thermal stability up to 200°C. The high conductivity of the needle‐like aggregates was ascribed to their well‐developed crystalline structures, compared with those of spherical particles. J. VINYL ADDIT. TECHNOL., 13:76–86, 2007. © 2007 Society of Plastics Engineers.