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  • 1
    Electronic Resource
    Electronic Resource
    High-temperature stimulated emission in optically pumped InGaN/GaN multiquantum wells (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 1623-1625 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Stimulated emission (SE) in optically pumped InGaN/GaN multiquantum well (MQW) structures grown by metalorganic chemical vapor deposition was experimentally studied in the temperature range of 175–575 K. The GaN barriers were intentionally doped with a different Si concentration ranging from 1×1017 to 3×1019 cm−3 and the effects of Si doping of GaN barriers on the optical properties of InGaN/GaN MQWs were investigated. The SE threshold was measured as a function of temperature and compared with bulk GaN. We observed that the SE threshold had a low value and a weak temperature dependence: for example, ∼25 kW/cm2 at 175 K, ∼55 kW/cm2 at 300 K, and ∼300 kW/cm2 at 575 K for one of the samples. Low SE thresholds are attributed to the high-quantum efficiency of the MQWs, possibly associated with the large localization of excitons. The characteristic temperature of 162 K was derived from the temperature dependence of the SE threshold. The integrated emission intensity versus pumping density was examined for different temperatures. This study shows that InGaN/GaN MQWs are suitable for development of laser diodes that can operate well above room temperature. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.121133
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  • 2
    Electronic Resource
    Electronic Resource
    Laser action in GaN pyramids grown on (111) silicon by selective lateral overgrowth (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 2242-2244 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Laser action was observed in GaN pyramids under strong optical pumping at room temperature. The pyramids were laterally overgrown on a patterned GaN/AlN seeding layer grown on a (111) silicon substrate by metal–organic chemical vapor deposition. Each pyramid had a 15-μm-wide hexagonal base and was on average 15 μm in height. The pyramids were individually pumped, imaged, and spectrally analyzed through a high-magnification telescope system using a high-density pulsed excitation source. Under high levels of optical pumping, multimode laser at room temperature was observed. The integrated emission intensity for both spontaneous and lasing peaks was studied as a function of excitation power density. The effects of pyramid geometry and short-pulse excitation on the multimode nature of laser oscillations inside of the pyramids is discussed. This study suggests that GaN microstructures could potentially be used as pixel elements and high-density two-dimensional laser arrays. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.121689
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  • 3
    Electronic Resource
    Electronic Resource
    Structural and optical characteristics of InxGa1−xN/GaN multiple quantum wells with different In compositions (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 2545-2547 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have studied the structural and optical properties of InxGa1−xN/GaN multiple quantum wells with different In compositions of 8.8%, 12.0%, and 13.3% by means of high-resolution x-ray diffraction (HRXRD), photoluminescence (PL), PL excitation (PLE), stimulated emission (SE), and time-resolved PL spectroscopy. As the In composition increases, the superlattice peaks in HRXRD measurements and the PLE band edge broaden, indicating the deterioration of interface quality due to the difficulty of uniform In incorporation into the GaN layer. However, the lower room-temperature SE threshold densities of the higher In concentration samples indicate that the effect of In suppressing nonradiative recombination overcomes the drawbacks associated with increasing interface imperfection. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.125072
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  • 4
    Electronic Resource
    Electronic Resource
    Stimulated emission in GaN thin films in the temperature range of 300–700 K (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 1792-1795 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the results of an experimental study on stimulated and spontaneous emission from high-quality single-crystal GaN films grown on 6H-SiC and (0001) sapphire substrates in the temperature range of 300–700 K. We observed edge-emitted stimulated emission (SE) at temperatures as high as 700 K for samples grown on both SiC and sapphire substrates. The energy position of the SE and spontaneous emission peaks were shown to shift linearly to longer wavelengths with temperature and empirical expressions for the energy positions are given. We demonstrate that the energy separation between the spontaneous and SE peaks gradually increases from 90 meV at 300 K to 200 meV at 700 K indicating that an electron-hole plasma is responsible for the SE mechanism in this temperature range. The temperature sensitivity of the SE threshold for different samples was studied and the characteristic temperature was found to be 173 K in the temperature range of 300–700 K for one of the samples studied. We suggest that the unique properties of SE in GaN thin films at high temperatures could potentially be utilized in optoelectronic devices. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369325
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  • 5
    Electronic Resource
    Electronic Resource
    Microencapsulation of Lactobacillus casei YIT 9018 using a Microporous Glass Membrane Emulsification System (2003)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 68 (2003), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: : Microporous glass (MPG) membrane emulsification was used for micro encapsulation of Lactoba-cillus casei YIT 9018. Several process parameters of membrane emulsification were investigated for producing a stable emulsion. The droplet dia in the emulsion depended upon the membrane pore size. The monodispersed emulsion obtained by this technique resulted in well-formed microcapsules with a narrow particle size distribution. For artificial gastric acid and bile, the viable count of encapsulated cells was constant through the incubation time, while the count of nonencapsulated cells was significantly decreased. A storage stability test at different temperatures resulted in a viability of encapsulated cells 3 to 5 log cycles higher than the viability of nonencapsulated cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.2003.tb14139.x
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  • 6
    Electronic Resource
    Electronic Resource
    Encapsulation of Fish Oil by an Enzymatic Gelation Process Using Transglutaminase Cross-linked Proteins (2003)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 68 (2003), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: To improve the storage stability and achieve controlled release, fish oil containing docosahexaenoic acid was encapsulated using double emulsification and subsequent enzymatic gelation method, using microbial transglutaminase cross-linked proteins. Isolated soy protein was selected as a wall material because it showed better emulsion stability and higher reactivity with MTGase than other proteins. Microcapsules prepared by this method showed a high stability against oxygen and a low water solubility, which subsequently resulted in sustained release of fish oil. Results indicate that this microencapsulation process is suitable for preparing protein-based microcapsules containing sensitive ingredients for controlled release and stability improvement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.2003.tb05794.x
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  • 7
    Electronic Resource
    Electronic Resource
    Evaluation of Process Parameters in the O/W/O Multiple Emulsion Method for Flavor Encapsulation (2003)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 68 (2003), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: : The multiple emulsion/cold dehydration method was developed for the flavor encapsulation. The effects of various process parameters on the emulsion stability and flavor retention were investigated. Microfluidizer (at 68 MPa) produced more stable emulsion with small uniform droplets than pressure-homogenizer. Increasing the gum arabic content created a highly viscous emulsion, which resulted in a stable O/W emulsion. The stability of an O/W/O multiple emulsion was highly affected by the type of emulsifiers and the most stable emulsion was prepared using the blend of Span 80 and PGPR. Well-formed microcapsules having high flavor retention (71%) was obtained when ethanol/water mixture solution of 9:1 was used as a dehydrating agent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.2003.tb05707.x
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  • 8
    Electronic Resource
    Electronic Resource
    Effects of Combined Treatment of High Hydrostatic Pressure and Mild Heat on the Quality of Carrot Juice (2001)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 66 (2001), S. 0 
    Details
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: : This study was performed to investigate the effects of the combined treatment of high pressure and heat on the quality of carrot juice, and to optimize the process condition. About 95% of food quality-related enzymes were lost at 400 MPa and 70 °C, for 10 min, while α- and β-carotene were relatively stable at the combined process. The optimum process condition was estimated at 395 to 445 MPa, 70 °C, for 8 to 11 min. These results indicate that the combined treatment of high pressure and mild heat could be used as an effective process for production of high-quality carrot juice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2621.2001.tb15214.x
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  • 9
    Electronic Resource
    Electronic Resource
    Slide film damping in laterally driven microstructures
    Amsterdam : Elsevier
    Sensors and Actuators A: Physical 40 (1994), S. 31-39 
    Details
    ISSN: 0924-4247
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0924-4247(94)85027-5
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  • 10
    Electronic Resource
    Electronic Resource
    Mechanical design issues in laterally-driven microstructures
    Amsterdam : Elsevier
    Sensors and Actuators A: Physical 23 (1990), S. 1060-1064 
    Details
    ISSN: 0924-4247
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0924-4247(90)87089-2
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