D. Vujic

Two-zone double phase conjugate mirror

An analysis of photorefractive (PR) oscillators consisting of two facing four-wave mixing regions is carried out. The threshold and operation conditions of different phase conjugate mirrors are discussed with the help of the grating action method. In particular, the threshold and the operation of the two-zone double phase conjugate mirror (DPCM) is compared with other related PR oscillators, the interconnected ring, and different connected DPCM.

Photorefractive oscillators that use internal-reflection modes

Using the grating-action method, we analyze the operation of photorefractive oscillators that use internal-reflection modes of the crystal. We show that the oscillators interacting with the lossless internal modes possess no thresholds for coupling strengths and require no finite input seed for stable operation. The onset of oscillation is like a second-order phase transition, in contrast to the lossy oscillators, whose onset is like a first-order phase transition.

Autologous Serum Eye Drops for Post-Chemical Injuries and Corneal Epithelial Defects

Abstract Aim: To evaluate success rate (efficacy, safety) in treatment of post-chemical injuries and corneal defects using autologous serum eye drops. Material and Methods: Authors reviewed 93 patients (116 eyes) hospitalized in Clinic of ophthalmology from 2010 to 2013, who had post-causoma corneal defects that were nonresponsive to conventional treatment and were treated with serum therapy. Authors correlated time of epithelialization of defects with rate of epithelial healing. Results: Authors investigated 93 patients (52 males, 41 females; aged 18 - 74) for treatment of corneal defects. Application of autologous serum therapy 56 (48.28%) of 116 eyes was healed in an average time of 4 weeks. Among 116 eyes, epithelial defects healed in 4 (3.45%) within 1 week, in additional 17 (14.65%) in 1-2 weeks, totalling 31 (26.72%) within 3 weeks. Five eyes (4.31%) completely healed at 5 week; three eyes (2.59%) had subsequent healing of epithelial defect at 6 week; 56 eyes completely healed within one month, and the remaining eight eyes healed within 1.5 month. Conclusion: Using serum therapy, it was managed to reduce time of healing from eleven weeks, which were necessary just couple years ago (before 2010) to four (maximum six) weeks to complete healing which are necessary today.

Interconnected ring oscillators

Threshold and operation conditions of the interconnected photorefractive ring oscillators are investigated, using the grating action method. Three types of two connected oscillators are considered, the first one consisting of two transmission grating crystals, the second one of two reflection grating crystals, and the third one of one transmission and one reflection grating crystal. It is found that, under similar conditions, the transmission-transmission ring possesses the lowest threshold and attains the highest reflectivity of the three.

Congenital blindness and visual impairment cause infection or non infection.

Conflict of interest: none declared. Introduction Authors are from reference documentation to archive at Organization of Federation of blind and visually impaired in central Serbia (Kragujevac), by retrograde analysis, of 2007-2012, comprehend two groups by etiology–clinical characteristics of congenital blindness and visually impaired, caused infection or non infection example. Aim to analyze relationship between infectious and non infectious of congenital blindness and visually impaired in our referent region and compare with world references. Material/methods With 6-years analysis included the most frequency cases of congenital blindness and visually impaired in two groups, according to presence or absence infectious causes. From infectious causes of congenital blindness and visually impaired are included: CMV – infection, congenital rubella syndrome, congenital toxoplasmosis, congenital syphilis and rare mixed syndrome. From non infectious causes are included: retinitis pigmentosa, retinopathy prematurity, primary congenital glaucoma, Leber’s congenital amaurosis and rare syndrome. Results: From total number of registered blind and visually impaired – 1308 (100%), over the last 6 years, the registration was 349 (26.68%) with congenital blindness and visually impaired. From recorder with the number of the most common congenital blindness and visually impaired–194 (55.59%) with infections cause, and 155 (44.41%) non infection cause. Conclusion: Congenital blindness has shown permanent increase in past 6 years, in group with infectious and with non infectious causes. Congenital blindness and visually impaired of the most common etiology among registered members of our association in Kragujevac is subject of our correlation and global trends mentioned observation of these diseases.

Adsorption of branched polymers on Sierpinski-type fractal of base \(\); exact results

Abstract:We have studied the branched polymers situated on the two-dimensional modified Sierpinski gasket lattice of base b=3in the presence of monomer-monomer and monomer-surface interactions. We have determined critical properties of this model and found that some surface crossover exponents differed much from that in the case of the standard SG.

Branched Polymers on the Two-Dimensional Square Lattice with Attractive Surfaces

AbstractUsing the renormalization group approach, an analysis is given of the asymptotic properties of branched polymers situated on the two-dimensional square lattice with attractive impenetrable surfaces. We modeled branched polymers as site lattice animals with loops and site lattice animals without loops on the simple square lattice. We found the gyration radius critical exponent ν=0.6511±0.0003 and ν=0.6513±0.0003 for branched polymers with and without loops, respectively. Our results for the crossover exponent φ=0.502±0.003 for branched polymers with loops and φ=0.503±0.003 for branched polymers without loops satisfy the recent hyperuniversality conjecture φ=

Adsorption on stepped substrates

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