• JLA Vol:21 Iss:4 (Use of dispersive Raman spectroscopy to detect the cytotoxic action of <em>viscum album</em> in adenocarcinoma of colon)

    Daniela Franco Lopes
    Institute of Research and Development (IP&D), Universidade do Vale do Parai´ba (UNIVAP), Av. Shishima Hifumi, 2911 Urbanova, 12244-000 Sa˜o Jose´ dos Campos, SP, Brazil

    Landulfo Silveira
    Group of Biomedical Engineering, Universidade Camilo Castelo Branco (UNICASTELO), Rod. Pres. Dutra, Km 138, Eugeˆnio de Melo, 12247-004 Sa˜o Jose´ dos Campos, SP, Brazil

    Marcelo Nobuo Sibata
    Aloi´sio Cunha de Carvalho
    Cristina Pacheco-Soares
    Jamil Saade
    Institute of Research and Development (IP&D), Universidade do Vale do Parai´ba (UNIVAP), Av. Shishima ...


  • JLA Vol:24 Iss:4 (Femtosecond laser welded nanostructures and plasmonic devices)

    A. Hu
    P. Peng
    H. Alarifi
    X. Y. Zhang
    J. Y. Guo
    Y. Zhou
    W. W. Duley

    Nanojoining, a burgeoning research area, becomes a key manufacturing of complicated nanodevices with functional prefabricated components. In this work, various nanojoining methods are first reviewed. For nanojoining of Ag/Au nanoparticles, three methods are investigated comparatively. Thermal annealing shows a two-step solid state diffusion mechanism. Laser annealing by millisecond pulses displays the thermal activated solid state diffusion. Meanwhile, two effects have been identified in femtosecond laser irradiation with diffe...


  • JLA Vol:5 Iss:2 (Characterization of Laser Produced High Molybdenum Surface Alloys on Stainless Steel Substrates)

    Dilip Kumar
    K. Sridhar
    A. R. Biswas
    G. L. Goswami
    M. B. Deshmukh

    High Mo surface alloys on stainless steels 304L and 316L were produced by laser surface alloying. For this, a layer of 60 μm thickness was overlaid on the substrates by plasma spraying of Mo powders. These were further treated by a Nd:YAG pulsed laser for alloying. Depths of alloying in the range of 440–1110 μm were achieved. Concentration in the range of 5.2–15.0 wt&percnt; Mo within the laser alloyed zone was, in general, uniform throughout. During alloying, in&hyphen;situ heating at 700°C was required to prevent cracking in samples wi...


  • JLA Vol:15 Iss:3 (Process characteristics and effects of gas- and water-atomized stainless steel powders in laser-based rapid tooling)

    Andrew J. Pinkerton
    Lin Li
    Department of Mechanical, Aerospace, and Manufacturing Engineering, Laser Processing Research Centre, UMIST, P.O. Box 88, Sackville Street, Manchester M60 1QD, United Kingdom

    In rapid tooling using the direct laser deposition process and stainless steel materials, only powders prepared using the gas-atomization method have been used because of their presumed superior flow characteristics. In this article, the use of water-atomized powder is investigated by comparing the behavior of the two types of 316 L powders, deposited using a CO2 laser and coaxial head. Results show little difference in the pneumatic conveyance of the po...


  • JLA Vol:19 Iss:3 (Rationale for laser classification measurement conditions)

    David H. Sliney
    Wesley J. Marshall
    E. Christopher Brumage
    Laser/Optical Radiation Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, Maryland 21010-5403

    The basic concept of laser hazard classification with four fundamental risk groups and several subclasses is well understood by most laser users. However, many readers of laser safety standards are frequently puzzled by the rigid measurement conditions applied for hazard classification, even if this is normally a task performed by the laser manufacturer and not by a laser user or a Laser Safety Officer. The historical rationale for the measurement conditi...


  • JLA Vol:24 Iss:5 (Flexible and efficient laser remote welding of ultra-thin metal foils)

    Andreas Patschger
    Jens Bliedtner
    University of Applied Science Jena, Carl-Zeiss-Promenade 2, Jena 07745, Germany

    Matthias Hild
    JENOPTIK Automatisierungstechnik GmbH, Konrad-Zuse-Straße 6, Jena 07745, Germany

    Jean Pierre Bergmann
    University of Technology Ilmenau, Neuhaus 1, Ilmenau 98693, Germany

    This paper discusses investigations regarding flexible and efficient strategies of laser remote welding of ultra-thin metal foils (≤50 μm) which are applied in the fields of electronics, packaging, and construction. A single-mode fiber laser was used, equipped with a scanner head and diverse objectives. Thus...


  • JLA Vol:7 Iss:1 (Photodynamic therapy)

    Leonard I. Grossweiner
    Physics Department, Illinois Institute of Technology, Chicago, IL 60616 and Wenske Laser Center, Ravenswood Hospital Medical Center, Chicago, IL 60664, U.S.A.

    Photodynamic therapy (PDT) is a new treatment for solid tumors utilizing the combined action of light and a photosensitizing drug. Laser–fiber optic delivery systems make it practical to treat superficial and interstitial cancers, including malignancies of the skin, head and neck, esophagus, endobronchial tract, stomach, urinary bladder, female genital tract, and other sites. The putative action mechanism in PDT involves photochemical destruction of tumor tissue membranes mediated by singlet...


  • JLA Vol:18 Iss:1 (An experimental and theoretical investigation of combined gas- and water-atomized powder deposition with a diode laser)

    Andrew J. Pinkerton
    Waheed Ul Haq Syed
    Lin Li
    Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Sackville Street Building, PO Box 88, Manchester M60 1QD, United Kingdom

    Functionally graded or composite components (FGCs) have been recognized as having immense potential for many industries. So far, deposition of compositionally graded alloys is the only method that has been shown to be a practical way to produce FGCs. In this work, a second way, that allows graded structures of a single material to be formed by direct metal deposition, is investigated. Simple component samples are bui...


  • JLA Vol:9 Iss:3 (In&hyphen;process monitoring of laser welding by the analysis of ripples in the plasma emission)

    Kiyokazu Mori
    Isamu Miyamoto

    A novel in&hyphen;process monitoring system employing two detectors set above the workpiece at different aiming angles of 5° and 75° has been developed to detect whether or not CO2 laser welding fully penetrates through to the back surface of steel sheets. The acquired signal contained a.c. components of the emission of the laser&hyphen;induced plasma in the plume and in the keyhole with frequencies up to approximately 10 kHz. The mean square value of the a.c. signal obtained by using the 75° sensor during full penetration welding was much larger than that of the partial penetration welding, showing that full p...


  • JLA Vol:4 Iss:1 (Laser Surfacing of High Density Polyethylene for Reduction in Fuel Permeability)

    W. W. Duley
    M. Ogmen
    T. Steel
    S. Mihailov

    The effect of UV and CO2 laser radiation on the surface of HDPE gas tank material in relation to the permeability of this surface to unleaded gasoline has been investigated. It is found that while excimer (UV) laser radiation has no effect on permeability, CO2 laser radiation at low intensity modifies the surface so as to reduce permeability over timescales of 1 – 2 days. A possible origin for this modification is suggested.



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