Mirbek TURDUEV

Article | 2023 | Physica Scripta98 ( 1 )

With the discovery of self-accelerating beams, possibility of obtaining curved light beams in free space has been realized. These special beams paved the way for many new applications as well as the exploration of novel beam types. Recently, great research effort has been conducted to realize different types of curved beams such as photonic hook and airy beam. These curved types of beams are obtained by introducing structural asymmetry or applying non-uniform dielectric distribution to the input and output face of the structure. With this regard, we propose specially designed asymmetric structure with polynomial back surface which g . . .enerates curved light beams. Proposed lossless dielectric structure can generate curved beams at frequencies varying from 15.78 GHz to 20.09 GHz and corresponding curvature angles of minimum 41.34 degrees and maximum 57.58 degrees, respectively. The physical background of the curved beam formation is based on interference of the exiting light waves that diffract on upper and bottom polynomial surfaces which provides phase modulation leading to the curved trajectory of the propagating light. In addition, the observed beam steering effect is further investigated and the experimental verification in microwave region is conducted to verify our design's operation principle More less

Zamirgül KAZAKBAYEVA

Proceedings Paper | 2016 | Journal of Physics: Conference Series737 ( 1 )

The interference spectral filters with amorphous silicon layer deposited by magnetron sputtering on the reflective metal layer on a glass substrate are developed. Interference filter select from white light source components corresponding to quasimonochromatic wavelength with a narrow bandwidth. The thickness of the amorphous silicon layer determines the center wavelength of the pass band of the filter. It proposed to use interference filter with amorphous silicon layer for direct laser recoding on it. Results on direct laser recording on amorphous silicon layer of the interference filter by single-mode Blu Ray laser (X = 405 nm) wi . . .th high contrast reflected image are demonstrated More less

Emil ÖMÜRZAK | Tinatin DOOLOTKELDİEVA | Saykal BOBUŞOVA

Proceedings Paper | 2018 | 2017 International Conference on Aerospace Technology, Communications and Energy Systems (ATCES 2017)302 ( UNSP 012075 )

By means of XRD and FESEM analysis, it is established that copper nanoparticles with sizes less than 10 nm are formed during the chemical reduction, which form aggregates mainly with spherical shape. Presence of gelatin during the chemical reduction of copper induced formation of smaller size distribution nanoparticles than that of nanoparticles synthesized without gelatin and it can be related to formation of protective layer. Synthesized Cu nano-powders have sufficiently high activity against the Erwinia amylovora bacterium, and the bacterial growth inhibition depends on the Cu nanoparticles concentration. At a concentration of 5 . . .mg / ml of Cu nanoparticles, the exciter growth inhibition zone reaches a maximum value within 72 hours and the lysis zone is 20 mm, and at a concentration of 1 mg / ml this value is 16 mm, which also indicates the significant antibacterial activity of this sample More less

Tinatin DOOLOTKELDİEVA | Emil ÖMÜRZAK

Article | 2018 | Materials Research Express5 ( 8 )

In the joint chemical reduction of silver and copper ions in the presence of gelatin, regardless of the composition of the reaction medium, a nanocomposite was formed consisting of nanodispersed silver and copper particles. In this research, the dependence of phase composition and dispersity on the synthesis conditions, as well as antibacterial activity of synthesized silver and copper nanocomposites were studied. It has been established that the most highly dispersed silver and copper nanocomposites were formed in an alkaline medium. We have revealed that nanocomposites of Ag-Cu system which were synthesized in an alkaline medium p . . .ossessed significant antibacterial activity against the Erwinia amylovora and Pseudomonas syringae bacteria More less

Emil ÖMÜRZAK | Ruslan ADİL AKAY TEGİN

Proceedings Paper | 2018 | 2017 International Conference on Aerospace Technology, Communications and Energy Systems (ATCES 2017)302 ( UNSP 012076 )

Pulsed plasma in liquid is a simple, ecologically friendly, cost-efficient method based on electrical discharge between two metal electrodes submerged into a dielectric liquid. We synthesized carbon-encapsulated Fe (Fe@C) magnetic nanoparticles with low cytotoxicity using pulsed plasma in a liquid. Body-centered cubic Fe core nanoparticles showed good crystalline structures with an average size between 20 and 30 nm were encapsulated in onion-like carbon coatings with a thickness of 2–10 nm. Thermal gravimetric analysis showed a high stability of the as-synthesized samples under thermal treatment and oxidation. Cytotoxicity measureme . . .nts showed higher cancer cell viability than samples synthesized by different methods. Carbon coated ZnO nanorods with about 20 nm thickness and 150 nm length were synthesized by this method using different surfactant materials such as cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS). Cu and Ag nanoparticles of about 10 nm in size were also synthesized by the pulsed plasma in aquatic solution of 0.2 ?elatine as surfactant material. These nanoparticles showed high antibacterial activity for Erwinia amylovora and Escherichia coli More less

Mehmet ERTUĞRUL

Article | 2022 | Nanotechnology33 ( 50 )

Colloidal quantum dots (QDs) are promising luminescent materials for display and lighting, but their stability has long been an issue. Here, we designed a passivation strategy of doping Ti ions into the shell of alloyed CdZnSeS@ZnS QDs. The results showed that Ti ions were successfully doped into the ZnS shell and the stability of QDs was improved. In the aging test, the Ti ions doped QDs maintained 51.4 of the initial performance after 90 h of aging, while the pristine QDs decreased to less than 25 of the initial value. In addition, we discuss the reasons why Ti ions doping improves the stability of QDs. Ti ions are found to form T . . .i-S bonds in the ZnS shell, which has high binding energy and strong oxidation resistance. Most importantly, since there is no external physical insulating coating, the optimized QDs can also be directly used in electroluminescent devices, showing great potential in electroluminescence applications More less

Mirbek TURDUEV

Article | 2022 | Journal of Physics D: Applied Physics55 ( 21 )

Logic gates have great importance in realization of rapid data transmission as well as low loss transfers. In this paper, a multi-objective inverse-design approach is implemented by using objective-first algorithm to design optical AND, OR, NAND and NOT logic gates on Si-platform at the design wavelength of 1.30 mu m. For all gates, the design area is fixed to 2.24 mu m x 2.24 mu m. The optical logic '1' output is accepted to be optical power values greater than 0.8 times of the input optical power. By implementing a Bias waveguide as well as two input ports, we made it possible to achieve logic '1' output for logic operations havin . . .g no inputs such as '0 NAND 0 1' and '0 NOT 1'. We binarized the proposed logic gates, and then numerically analyzed them by using finite-difference time-domain method. Proposed AND gate yields 1.20 times of input power for '1 AND 1 1' logic operation and highest logic '0' is obtained for logic operation of '1 AND 0 0' as 0.40 times of the input power at the operating wavelength. It is also observed that proposed logic gates can operate not only at the design wavelength of 1.30 mu m but also at broad wavelength regions as well. Finally, we demonstrate that it is possible to carry out complex logic operations by combining the proposed logic AND, OR and NAND gates to construct an XOR gate in the same platform More less