Kalms et al. focused on developing a setup that would be mobile enough to easily set up in a museum environment and be stable enough to provide interferograms that were sensitive to changes in the painting after thermal loading, but not sensitive to slight environmental changes in the surrounding conditions [108, 109]. The sensitivity of the phase maps obtained through laser shearography helps researchers observe defects such as cracks, paint losses, and delaminations more easily, especially if the defects are subsurface. The maps are also capable of serving as a diagnostic tool for cultural heritage, guiding attention to areas that need more immediate attention during a conservation survey. The sensitivity of laser shearography to detect delaminations, impacts on a painting surface, and the propagation of cracks through paint layers was successfully demonstrated with mockup samples [110]. The use of strain maps to show the potential areas of concern and highlight areas of potential degradation in the paintings have been optimized for ease of interpretation by conservators [111]. Shearography has also been paired with other imaging techniques such as terahertz imaging, fringe projections to observe 3D topographic maps, and reflectance transformation imaging to provide more complete datasets for diagnosing defects and changes in a painting after environmental fluctuations or transport [107, 112, 113]. Some optimization of strain maps from the displacement gradients was also performed on a test painting to quantify the strain experienced by a painting as a result of cycling lights in a museum setting [107, 114]. Comparing the phase maps of defects in paintings to simulated phase maps generated using finite element analysis (see Section 7.2), allow researchers to understand the nature of defects within a painting and to vary the parameters of the defect until the simulated map matches the experimentally observed map, which can be useful for understanding how different defects/areas of degradation within a painting can affect the resulting phase map [115].
Crack 1 Touch Laser Photo.epub
Cyclodestructive procedures areuseful tools in managing refractory PCG after all other options have beentried, to reduce aqueous production. Results are unpredictable andcomplications exist. Laser cyclophotocoagulation (CPC) has largely replacedcyclocryotherapy, and diode laser is preferred to Nd:YAG laser due to decreasedadverse events such as sympathetic ophthalmia. Transscleral and endoscopicapplication of laser are both options, with endoscopic preferred if the eyeanatomy allows. Transscleral Micropulse-CPC may have less severe complicationsthan traditional transscleral CPC and be as effective in children,[87] though further research is needed. The limbal anatomymay be distorted and blind application of transscleral CPC may be better guidedwith ultrasound biomicroscopy.[88] A general rule ofthumb for all cyclodestructive procedures is to maintain 1-2 clock hours ofuntouched ciliary processes, even after repeated sessions, thus carefuldocumentation of treated areas is recommended. Rare complications includehypotony, retinal detachment, visual loss, and phthisis. 2ff7e9595c
Comments