The Experts below are selected from a list of 2751 Experts worldwide ranked by ideXlab platform
Ashish Kumar Nath - One of the best experts on this subject based on the ideXlab platform.
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Development of a water-jet assisted laser Paint Removal process
Applied Surface Science, 2013Co-Authors: Yuvraj K. Madhukar, Suvradip Mullick, Ashish Kumar NathAbstract:Abstract The laser Paint Removal process usually leaves behind traces of combustion product i.e. ashes on the surface. An additional post-processing such as light-brushing or wiping by some mechanical means is required to remove the residual ash. In order to strip out the Paint completely from the surface in a single step, a water-jet assisted laser Paint Removal process has been investigated. The 1.07 μm wavelength of Yb-fiber laser radiation has low absorption in water; therefore a high power fiber laser was used in the experiment. The laser beam was delivered on the Paint-surface along with a water jet to remove the Paint and residual ashes effectively. The specific energy, defined as the laser energy required removing a unit volume of Paint was found to be marginally more than that for the gas-jet assisted laser Paint Removal process. However, complete Paint Removal was achieved with the water-jet assist only. The relatively higher specific energy in case of water-jet assist is mainly due to the scattering of laser beam in the turbulent flow of water-jet.
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effect of laser operating mode in Paint Removal with a fiber laser
Applied Surface Science, 2013Co-Authors: Yuvraj K. Madhukar, Suvradip Mullick, Dinesh K Shukla, Shailesh Kumar, Ashish Kumar NathAbstract:Abstract The laser Paint Removal behavior with the continuous wave (CW) beam and repetitive pulses has been investigated using an Yb:fiber laser. The specific energy, which is defined as the amount of laser energy needed to remove unit volume of Paint prior to the onset of substrate damage and is a measure of the process efficiency, was found to be dependent on the laser processing parameters. In CW mode the specific energy reduced with the increase of laser scan speed and corresponding increase of laser power. In case of repetitive pulsed mode the specific energy was found to depend on the pulse on-time as well as on the time interval between two successive pulses. At 1 kHz repetition rate, the specific energy reduced with the increase of duty cycle and corresponding increase in scanning speed, but at relatively low frequencies of 50–150 Hz and 50% overlap between two pulses specific energy was found to increase with increasing duty cycle. Irrespective of the mode of operation specific energy increased with the increase of average line energy. During the laser Paint irradiation a plume of burning fume was formed over the surface and the variation in specific energy with laser processing parameters has been attributed to the absorption of laser radiation in the plume. Since the dimension of plume and fume particle density in it will depend on the laser energy absorbed in Paint, the absorption loss in plume will depend on the laser parameters. This was confirmed by measuring the plume temperature for different laser processing conditions. Based on this and considering that the actual specific energy absorbed by Paint should be constant, the absorption characteristic of plume was modeled applying Beer Lambert's law.
Yuvraj K. Madhukar - One of the best experts on this subject based on the ideXlab platform.
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Development of a water-jet assisted laser Paint Removal process
Applied Surface Science, 2013Co-Authors: Yuvraj K. Madhukar, Suvradip Mullick, Ashish Kumar NathAbstract:Abstract The laser Paint Removal process usually leaves behind traces of combustion product i.e. ashes on the surface. An additional post-processing such as light-brushing or wiping by some mechanical means is required to remove the residual ash. In order to strip out the Paint completely from the surface in a single step, a water-jet assisted laser Paint Removal process has been investigated. The 1.07 μm wavelength of Yb-fiber laser radiation has low absorption in water; therefore a high power fiber laser was used in the experiment. The laser beam was delivered on the Paint-surface along with a water jet to remove the Paint and residual ashes effectively. The specific energy, defined as the laser energy required removing a unit volume of Paint was found to be marginally more than that for the gas-jet assisted laser Paint Removal process. However, complete Paint Removal was achieved with the water-jet assist only. The relatively higher specific energy in case of water-jet assist is mainly due to the scattering of laser beam in the turbulent flow of water-jet.
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effect of laser operating mode in Paint Removal with a fiber laser
Applied Surface Science, 2013Co-Authors: Yuvraj K. Madhukar, Suvradip Mullick, Dinesh K Shukla, Shailesh Kumar, Ashish Kumar NathAbstract:Abstract The laser Paint Removal behavior with the continuous wave (CW) beam and repetitive pulses has been investigated using an Yb:fiber laser. The specific energy, which is defined as the amount of laser energy needed to remove unit volume of Paint prior to the onset of substrate damage and is a measure of the process efficiency, was found to be dependent on the laser processing parameters. In CW mode the specific energy reduced with the increase of laser scan speed and corresponding increase of laser power. In case of repetitive pulsed mode the specific energy was found to depend on the pulse on-time as well as on the time interval between two successive pulses. At 1 kHz repetition rate, the specific energy reduced with the increase of duty cycle and corresponding increase in scanning speed, but at relatively low frequencies of 50–150 Hz and 50% overlap between two pulses specific energy was found to increase with increasing duty cycle. Irrespective of the mode of operation specific energy increased with the increase of average line energy. During the laser Paint irradiation a plume of burning fume was formed over the surface and the variation in specific energy with laser processing parameters has been attributed to the absorption of laser radiation in the plume. Since the dimension of plume and fume particle density in it will depend on the laser energy absorbed in Paint, the absorption loss in plume will depend on the laser parameters. This was confirmed by measuring the plume temperature for different laser processing conditions. Based on this and considering that the actual specific energy absorbed by Paint should be constant, the absorption characteristic of plume was modeled applying Beer Lambert's law.
Suvradip Mullick - One of the best experts on this subject based on the ideXlab platform.
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Development of a water-jet assisted laser Paint Removal process
Applied Surface Science, 2013Co-Authors: Yuvraj K. Madhukar, Suvradip Mullick, Ashish Kumar NathAbstract:Abstract The laser Paint Removal process usually leaves behind traces of combustion product i.e. ashes on the surface. An additional post-processing such as light-brushing or wiping by some mechanical means is required to remove the residual ash. In order to strip out the Paint completely from the surface in a single step, a water-jet assisted laser Paint Removal process has been investigated. The 1.07 μm wavelength of Yb-fiber laser radiation has low absorption in water; therefore a high power fiber laser was used in the experiment. The laser beam was delivered on the Paint-surface along with a water jet to remove the Paint and residual ashes effectively. The specific energy, defined as the laser energy required removing a unit volume of Paint was found to be marginally more than that for the gas-jet assisted laser Paint Removal process. However, complete Paint Removal was achieved with the water-jet assist only. The relatively higher specific energy in case of water-jet assist is mainly due to the scattering of laser beam in the turbulent flow of water-jet.
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effect of laser operating mode in Paint Removal with a fiber laser
Applied Surface Science, 2013Co-Authors: Yuvraj K. Madhukar, Suvradip Mullick, Dinesh K Shukla, Shailesh Kumar, Ashish Kumar NathAbstract:Abstract The laser Paint Removal behavior with the continuous wave (CW) beam and repetitive pulses has been investigated using an Yb:fiber laser. The specific energy, which is defined as the amount of laser energy needed to remove unit volume of Paint prior to the onset of substrate damage and is a measure of the process efficiency, was found to be dependent on the laser processing parameters. In CW mode the specific energy reduced with the increase of laser scan speed and corresponding increase of laser power. In case of repetitive pulsed mode the specific energy was found to depend on the pulse on-time as well as on the time interval between two successive pulses. At 1 kHz repetition rate, the specific energy reduced with the increase of duty cycle and corresponding increase in scanning speed, but at relatively low frequencies of 50–150 Hz and 50% overlap between two pulses specific energy was found to increase with increasing duty cycle. Irrespective of the mode of operation specific energy increased with the increase of average line energy. During the laser Paint irradiation a plume of burning fume was formed over the surface and the variation in specific energy with laser processing parameters has been attributed to the absorption of laser radiation in the plume. Since the dimension of plume and fume particle density in it will depend on the laser energy absorbed in Paint, the absorption loss in plume will depend on the laser parameters. This was confirmed by measuring the plume temperature for different laser processing conditions. Based on this and considering that the actual specific energy absorbed by Paint should be constant, the absorption characteristic of plume was modeled applying Beer Lambert's law.
Andreas W Momber - One of the best experts on this subject based on the ideXlab platform.
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de Painting with high speed water jets Paint Removal process and substrate surface roughness
Progress in Organic Coatings, 2010Co-Authors: H Teimourian, Mohammadreza Shabgard, Andreas W MomberAbstract:Although the use of water jets for Paint Removal processes is an accepted procedure, there are just a few studies known which discuss parameter optimization and surface topography in some detail. The paper investigates the effects of water jet kinetic energy and stand-off distance on the mass loss of an organic Paint system applied to a steel substrate. It was shown that the material Removal process was characterized by a combination of loading intensity and loading frequency. Water drops, formed in the water jet at long stand-off distances, played a notable role. For rather high water jet energies, mass loss exhibited high values at high stand-off distances. For lower water jet energies, however, maximum material loss values appeared at a critical stand-off distance. The transition water jet energy was 600 kJ. It could be shown that the steel substrate topography was not compromised due to secondary surface preparation by water jets. Secondary blast cleaning, however, reduced the profile of the substrate.
Gerald Borgia - One of the best experts on this subject based on the ideXlab platform.
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bower Paint Removal leads to reduced female visits suggesting bower Paint functions as a chemical signal
Animal Behaviour, 2013Co-Authors: Reimi E Hicks, Archer Larned, Gerald BorgiaAbstract:The multifaceted courtship display of male satin bowerbirds, Ptilonorhynchus violaceus, involves several elements that have been studied in detail. However, one of their most unique display elements, bower Painting, has received relatively little attention despite males' large investment of time in this behaviour. Male bowerbirds chew plant material and apply the resulting mixture of masticated vegetation and male saliva or ‘bower Paint’ to a chest-high band inside their bower walls. Searching females taste this Paint, suggesting that Paint may be a chemosensory signal. We used both behavioural observations and experimental approaches to examine predictions made by two hypotheses for the function of bower Paint. We measured natural variation in Paint quantity to investigate whether quantity of Paint at bowers is related to other male display traits, male mating success and male physical condition. We also investigated whether males and females are affected by experimental Removal of bower Paint. Additionally, we assessed male response to Paint transplants from other individuals. We found a significant correlation between the amount of Paint and a composite estimate of several other measures known to indicate bower and decoration display quality. Also, males whose bowers underwent experimental Removal of Paint had fewer females return for second courtships and copulations than did control males. This result provides the first experimental evidence that females respond to bower Paint. These findings establish that bower Paint is a trait that affects mate-searching decisions by females and demonstrates that the quantity of bower Paint is important in attracting females.
