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Power Laser (power + laser)

Distribution by Scientific Domains
Polymers and Materials Science42%

Kinds of Power Laser

  • high power laser
    		•

    Selected Abstracts

    Investigations into the Sealing of Heat Damaged Areas by Applying Polymer Powders During Laser Cutting of Carbon Fiber Reinforced Composites,

    ADVANCED ENGINEERING MATERIALS, Issue 7 2010
    Peter Jaeschke
    Endless carbon fiber reinforced plastics are recognized as having the greatest lightweight construction potential of all materials. Fully automated process chains for the manufacturing of composite structures are needed in order to achieve production rates and cycle times required in many industrial sectors. In this paper, a new technique, based on the in situ sealing of the kerf during high power laser cutting by application of polymer powder is presented. The degree of sealing is analyzed as a function of powder mass flow as well as carrying gas flow and it is shown that moisture uptake can be reduced compared to unsealed laser cut specimens. [source]

    Nanofibers from Laser Spinning: Laser Spinning of Bioactive Glass Nanofibers (Adv. Funct.

    ADVANCED FUNCTIONAL MATERIALS, Issue 19 2009
    Mater.
    This cover image is a graphical representation of the laser spinning process described by Félix Quintero et al. on page 3084. Laser spinning involves the use of a high power laser to melt a very small volume from a plate of the precursor material. A high speed supersonic gas jet causes the rapid elongation and cooling of the melt, yielding a glass nanofiber. The authors also describe the use of this technique in producing Bioglass nanofibers. [source]

    Luminescence of Nanocrystalline Erbium-Doped Yttria

    ADVANCED FUNCTIONAL MATERIALS, Issue 5 2009
    Yuanbing Mao
    Abstract In this paper, the luminescence, including photoluminescence, upconversion and cathodoluminescence, from single-crystalline erbium-doped yttria nanoparticles with an average diameter of 80,nm, synthesized by a molten salt method, is reported. Outstanding luminescent properties, including sharp and well-resolved photoluminescent lines in the infrared region, outstanding green and red upconversion emissions, and excellent cathodoluminescence, are observed from the nanocrystalline erbium-doped yttria. Moreover, annealing by the high power laser results in a relatively large increase in photoluminescent emission intensity without causing spectral line shift. These desirable properties make these nanocrystals promising for applications in display, bioanalysis and telecommunications. [source]

    Laser phototherapy as topical prophylaxis against head and neck cancer radiotherapy-induced oral mucositis: Comparison between low and high/low power lasers

    LASERS IN SURGERY AND MEDICINE, Issue 4 2009
    Alyne Simões PhD
    Abstract Background and Objective Oral mucositis is a dose-limiting and painful side effect of radiotherapy (RT) and/or chemotherapy in cancer patients. The purpose of the present study was to analyze the effect of different protocols of laser phototherapy (LPT) on the grade of mucositis and degree of pain in patients under RT. Patients and Methods Thirty-nine patients were divided into three groups: G1, where the irradiations were done three times a week using low power laser; G2, where combined high and low power lasers were used three time a week; and G3, where patients received low power laser irradiation once a week. The low power LPT was done using an InGaAlP laser (660 nm/40 mW/6 J,cm,2/0.24 J per point). In the combined protocol, the high power LPT was done using a GaAlAs laser (808 nm, 1 W/cm2). Oral mucositis was assessed at each LPT session in accordance to the oral-mucositis scale of the National Institute of the Cancer,Common Toxicity criteria (NIC-CTC). The patient self-assessed pain was measured by means of the visual analogue scale. Results All protocols of LPT led to the maintenance of oral mucositis scores in the same levels until the last RT session. Moreover, LPT three times a week also maintained the pain levels. However, the patients submitted to the once a week LPT had significant pain increase; and the association of low/high LPT led to increased healing time. Conclusions These findings are desired when dealing with oncologic patients under RT avoiding unplanned radiation treatment breaks and additional hospital costs. Lasers Surg. Med. 41:264,270, 2009. © 2009 Wiley-Liss, Inc. [source]

    Laser-induced phase changes in olivine FePO4: a warning on characterizing LiFePO4 -based cathodes with Raman spectroscopy

    JOURNAL OF RAMAN SPECTROSCOPY, Issue 2 2009
    Christopher M. Burba
    Abstract Raman spectroscopy is an excellent technique for probing lithium intercalation reactions of many diverse lithium ion battery electrode materials. The technique is especially useful for probing LiFePO4 -based cathodes because the intramolecular vibrational modes of the PO43, anions yield intense bands in the Raman spectrum, which are sensitive to the presence of Li+ ions. However, the high power lasers typically used in Raman spectroscopy can induce phase transitions in solid-state materials. These phase transitions may appear as changes in the spectroscopic data and could lead to erroneous conclusions concerning the delithiation mechanism of LiFePO4. Therefore, we examine the effect of exposing olivine FePO4 to a range of power settings of a 532-nm laser. Laser power settings higher than 1.3 W/mm2 are sufficient to destroy the FePO4 crystal structure and result in the formation of disordered FePO4. After the laser is turned off, the amorphous FePO4 compound crystallizes in the electrochemically inactive ,-FePO4 phase. The present experimental results strongly suggest that the power setting of the excitation laser should be carefully controlled when using Raman spectroscopy to characterize fundamental lithium ion intercalation processes of olivine materials. In addition, Raman spectra of the amorphous intermediate might provide insight into the ,-FePO4 to olivine FePO4 phase transition that is known to occur at temperatures higher than 450 °C. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Laser phototherapy as topical prophylaxis against head and neck cancer radiotherapy-induced oral mucositis: Comparison between low and high/low power lasers

    LASERS IN SURGERY AND MEDICINE, Issue 4 2009
    Alyne Simões PhD
    Abstract Background and Objective Oral mucositis is a dose-limiting and painful side effect of radiotherapy (RT) and/or chemotherapy in cancer patients. The purpose of the present study was to analyze the effect of different protocols of laser phototherapy (LPT) on the grade of mucositis and degree of pain in patients under RT. Patients and Methods Thirty-nine patients were divided into three groups: G1, where the irradiations were done three times a week using low power laser; G2, where combined high and low power lasers were used three time a week; and G3, where patients received low power laser irradiation once a week. The low power LPT was done using an InGaAlP laser (660 nm/40 mW/6 J,cm,2/0.24 J per point). In the combined protocol, the high power LPT was done using a GaAlAs laser (808 nm, 1 W/cm2). Oral mucositis was assessed at each LPT session in accordance to the oral-mucositis scale of the National Institute of the Cancer,Common Toxicity criteria (NIC-CTC). The patient self-assessed pain was measured by means of the visual analogue scale. Results All protocols of LPT led to the maintenance of oral mucositis scores in the same levels until the last RT session. Moreover, LPT three times a week also maintained the pain levels. However, the patients submitted to the once a week LPT had significant pain increase; and the association of low/high LPT led to increased healing time. Conclusions These findings are desired when dealing with oncologic patients under RT avoiding unplanned radiation treatment breaks and additional hospital costs. Lasers Surg. Med. 41:264,270, 2009. © 2009 Wiley-Liss, Inc. [source]