The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Sandip P. Harimkar - One of the best experts on this subject based on the ideXlab platform.

  • evolution of geometric and quality features during ultrasonic vibration assisted Continuous Wave Laser surface drilling
    Journal of Materials Processing Technology, 2016
    Co-Authors: Habib S Alavi, Sandip P. Harimkar
    Abstract:

    Abstract Recently, the processes involving simultaneous application of ultrasonic vibrations during conventional materials processing are attracting significant interests for improving process efficiency and material quality. It has been previously shown that the simultaneous application of ultrasonic vibrations (frequency of 20 kHz and vibration displacement of 23 μm) during Continuous Wave (CW) CO2 Laser surface melting results in melt expulsion and formation of surface holes. In this paper, a systematic evolution of geometric features (hole depth, diameter, aspect ratio, and taper) and quality parameters (material build-up, spatter, recast layer thickness, and heat affected zone) of holes with Laser irradiation time (0.05, 0.1, 0.2, 0.25, 0.35, 0.75, and 1.25 s) for the ultrasonic vibration-assisted CW CO2 Laser surface drilling of AISI 316 stainless steel is investigated. Also, a multi-step finite element analysis, taking into account the observations of melt expulsion from high speed photography, is presented for the prediction of Laser drilled hole volume. The results indicate that the Laser melting regime of the Continuous Wave Laser-material interactions can be extended for drilling of materials, expanding the applications of these widely used Lasers for flexible manufacturing.

  • Ultrasonic vibration-assisted Continuous Wave Laser surface drilling of materials
    Manufacturing letters, 2015
    Co-Authors: S. Habib Alavi, Sandip P. Harimkar
    Abstract:

    Abstract Melt expulsion and surface vaporization are important material removal mechanisms of pulsed Laser drilling of materials. Drilling rate and quality of Laser drilled holes depend on the material removal mechanism and are important considerations during Laser drilling. In this letter, a novel ultrasonic vibration-assisted Continuous Wave Laser drilling of materials is reported. The application of ultrasonic vibrations during Laser surface melting facilitated melt expulsion from the surface, creating holes. Preliminary analysis of the material removal mechanisms and the effect of ultrasonic vibration amplitude on the geometric features are presented for the ultrasonic vibration assisted Laser drilling of austenitic stainless steels.

Habib S Alavi - One of the best experts on this subject based on the ideXlab platform.

  • evolution of geometric and quality features during ultrasonic vibration assisted Continuous Wave Laser surface drilling
    Journal of Materials Processing Technology, 2016
    Co-Authors: Habib S Alavi, Sandip P. Harimkar
    Abstract:

    Abstract Recently, the processes involving simultaneous application of ultrasonic vibrations during conventional materials processing are attracting significant interests for improving process efficiency and material quality. It has been previously shown that the simultaneous application of ultrasonic vibrations (frequency of 20 kHz and vibration displacement of 23 μm) during Continuous Wave (CW) CO2 Laser surface melting results in melt expulsion and formation of surface holes. In this paper, a systematic evolution of geometric features (hole depth, diameter, aspect ratio, and taper) and quality parameters (material build-up, spatter, recast layer thickness, and heat affected zone) of holes with Laser irradiation time (0.05, 0.1, 0.2, 0.25, 0.35, 0.75, and 1.25 s) for the ultrasonic vibration-assisted CW CO2 Laser surface drilling of AISI 316 stainless steel is investigated. Also, a multi-step finite element analysis, taking into account the observations of melt expulsion from high speed photography, is presented for the prediction of Laser drilled hole volume. The results indicate that the Laser melting regime of the Continuous Wave Laser-material interactions can be extended for drilling of materials, expanding the applications of these widely used Lasers for flexible manufacturing.

Andreas J Gross - One of the best experts on this subject based on the ideXlab platform.

  • Bladder neck incision using a 70 W 2 micron Continuous Wave Laser (RevoLix)
    World Journal of Urology, 2007
    Co-Authors: Thorsten Bach, Thomas R W Herrmann, Christian Cellarius, Andreas J Gross
    Abstract:

    Postoperative bladder neck contracture continues to be a frequently occurring problem. Bladder neck incision (BNI) continues to be the standard mode of treatment. However, the recurrence rate appears to be high. Therefore alternative treatment options are still needed. We report about initial experience with the RevoLix 2 micron Continuous Wave Laser for BNI after a 1-year follow-up. Fourteen patients with a second or third recurrence of bladder neck contracture after primary surgery were included into the trial. All patients reported high-grade obstruction and residual urine. BNI was performed using a 70 W 2-micron Continuous Wave Laser (RevoLix). This Laser utilizes the thulium as an active ion. Laser incisions were applied in 5 and 7o’clock lithotomy position. Remaining tissue was vaporized. Assessed outcomes were improvement in AUA-symptom-score, quality of life index and uroflowmetry, measured preoperatively, after 2 and 12 months postoperatively. Mean operating time was 7 min, mean catheterization time was 6.5 h. The mean maximum uroflow-rate improved from 9 ml/s preoperatively to 23 ml/s. AUA-symptom score improved from 22 to 8 points and quality of life index improved from four to one. Two patients developed restenosis so far. Although longer follow-up and larger sample size are needed, BNI with the RevoLix Laser is a fast, safe and promising procedure in recurrent bladder neck sclerosis.

  • bladder neck incision using a 70 w 2 micron Continuous Wave Laser revolix
    World Journal of Urology, 2007
    Co-Authors: Thorsten Bach, Thomas R W Herrmann, Christian Cellarius, Andreas J Gross
    Abstract:

    Postoperative bladder neck contracture continues to be a frequently occurring problem. Bladder neck incision (BNI) continues to be the standard mode of treatment. However, the recurrence rate appears to be high. Therefore alternative treatment options are still needed. We report about initial experience with the RevoLix 2 micron Continuous Wave Laser for BNI after a 1-year follow-up. Fourteen patients with a second or third recurrence of bladder neck contracture after primary surgery were included into the trial. All patients reported high-grade obstruction and residual urine. BNI was performed using a 70 W 2-micron Continuous Wave Laser (RevoLix). This Laser utilizes the thulium as an active ion. Laser incisions were applied in 5 and 7o’clock lithotomy position. Remaining tissue was vaporized. Assessed outcomes were improvement in AUA-symptom-score, quality of life index and uroflowmetry, measured preoperatively, after 2 and 12 months postoperatively. Mean operating time was 7 min, mean catheterization time was 6.5 h. The mean maximum uroflow-rate improved from 9 ml/s preoperatively to 23 ml/s. AUA-symptom score improved from 22 to 8 points and quality of life index improved from four to one. Two patients developed restenosis so far. Although longer follow-up and larger sample size are needed, BNI with the RevoLix Laser is a fast, safe and promising procedure in recurrent bladder neck sclerosis.

Shoujun Ding - One of the best experts on this subject based on the ideXlab platform.

  • crystal growth spectral properties and Continuous Wave Laser operation of new mixed nd gdynbo4 Laser crystal
    Journal of Alloys and Compounds, 2017
    Co-Authors: Shoujun Ding, Qingli Zhang, Fang Peng, Wenpeng Liu, Jianqiao Luo, Renqin Dou, Guihua Sun, Xiaofei Wang
    Abstract:

    Abstract A new mixed Laser crystal Nd:Gd 0.69 Y 0.3 NbO 4 (Nd:GYNO) with high quality was grown successfully by Czochralski method. Its structure parameters are obtained by the X-ray Rietveld refinement method. The effective segregation coefficient of Nd 3+ ions is 0.61 in GYNO host. The maximum absorption cross section at 809 nm and peak emission cross section at 1065.6 nm of Nd:GYNO crystal are 11.6 × 10 −20 and 20.5 × 10 −20  cm 2 , respectively. The fluorescence lifetime of 4 F 3/2 manifold for Nd 3+ in Nd:GYNO crystal is fitted to be 156 μs. Diode-pumped Continuous-Wave Laser operations at 1.06 μm with Nd:GYNO crystals cut perpendicular to crystallographic a , b , and c axes (denoted as a -, b - c -cut, respectively) were demonstrated. A maximum output power of 0.98 W was obtained with c -cut crystal, corresponding to an optical-to-optical conversion efficiency of 31.3% and a slope efficiency of 30.4%. All these results imply that the Nd:GYNO crystal has great potential application in low and even moderate Lasers.

Thorsten Bach - One of the best experts on this subject based on the ideXlab platform.

  • Bladder neck incision using a 70 W 2 micron Continuous Wave Laser (RevoLix)
    World Journal of Urology, 2007
    Co-Authors: Thorsten Bach, Thomas R W Herrmann, Christian Cellarius, Andreas J Gross
    Abstract:

    Postoperative bladder neck contracture continues to be a frequently occurring problem. Bladder neck incision (BNI) continues to be the standard mode of treatment. However, the recurrence rate appears to be high. Therefore alternative treatment options are still needed. We report about initial experience with the RevoLix 2 micron Continuous Wave Laser for BNI after a 1-year follow-up. Fourteen patients with a second or third recurrence of bladder neck contracture after primary surgery were included into the trial. All patients reported high-grade obstruction and residual urine. BNI was performed using a 70 W 2-micron Continuous Wave Laser (RevoLix). This Laser utilizes the thulium as an active ion. Laser incisions were applied in 5 and 7o’clock lithotomy position. Remaining tissue was vaporized. Assessed outcomes were improvement in AUA-symptom-score, quality of life index and uroflowmetry, measured preoperatively, after 2 and 12 months postoperatively. Mean operating time was 7 min, mean catheterization time was 6.5 h. The mean maximum uroflow-rate improved from 9 ml/s preoperatively to 23 ml/s. AUA-symptom score improved from 22 to 8 points and quality of life index improved from four to one. Two patients developed restenosis so far. Although longer follow-up and larger sample size are needed, BNI with the RevoLix Laser is a fast, safe and promising procedure in recurrent bladder neck sclerosis.

  • bladder neck incision using a 70 w 2 micron Continuous Wave Laser revolix
    World Journal of Urology, 2007
    Co-Authors: Thorsten Bach, Thomas R W Herrmann, Christian Cellarius, Andreas J Gross
    Abstract:

    Postoperative bladder neck contracture continues to be a frequently occurring problem. Bladder neck incision (BNI) continues to be the standard mode of treatment. However, the recurrence rate appears to be high. Therefore alternative treatment options are still needed. We report about initial experience with the RevoLix 2 micron Continuous Wave Laser for BNI after a 1-year follow-up. Fourteen patients with a second or third recurrence of bladder neck contracture after primary surgery were included into the trial. All patients reported high-grade obstruction and residual urine. BNI was performed using a 70 W 2-micron Continuous Wave Laser (RevoLix). This Laser utilizes the thulium as an active ion. Laser incisions were applied in 5 and 7o’clock lithotomy position. Remaining tissue was vaporized. Assessed outcomes were improvement in AUA-symptom-score, quality of life index and uroflowmetry, measured preoperatively, after 2 and 12 months postoperatively. Mean operating time was 7 min, mean catheterization time was 6.5 h. The mean maximum uroflow-rate improved from 9 ml/s preoperatively to 23 ml/s. AUA-symptom score improved from 22 to 8 points and quality of life index improved from four to one. Two patients developed restenosis so far. Although longer follow-up and larger sample size are needed, BNI with the RevoLix Laser is a fast, safe and promising procedure in recurrent bladder neck sclerosis.