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21.
Generation of doubly charged vortex beam by concentrated loading of glass disks along their diameter
We show that a system of glass disks compressed along their diameters enables one to induce a doubly charged vortex beam in the emergent light when the incident light is circularly polarized. Using such a disk system, one can control the efficiency of conversion of the spin angular momentum to the orbital angular momentum by a loading force. The consideration presented here can be extended for the case of crystalline materials with high optical damage thresholds in order to induce high-power vortex beams. 相似文献
22.
Oleh Shpotyuk Adam Ingram Zdenka Bujkov Peter Bal Yaroslav Shpotyuk Dmytro Slobodzyan Mariusz Wo
ny Catherine Boussard‐Pledel Bruno Bureau 《Polymer Engineering and Science》2019,59(12):2438-2442
The method of positron annihilation lifetime (PAL) spectroscopy was first employed to study atomic‐deficient free‐volume structure of nanocomposites prepared by high‐energy mechanical milling of glassy g‐As2Se3 in water solution of polyvinylpyrrolidone (PVP). The formalism of x3‐x2‐CDA (coupling decomposition algorithm) describing conversion of bound positron‐electron (positronium Ps) states into positron traps was applied to identify free‐volume elements in pelletized PVP‐capped g‐As2Se3 nanocomposite in respect to parent dry‐milled g‐As2Se3. Under wet milling, the internanoparticle Ps‐decaying sites in preferential PVP environment were shown to replace free‐volume positron traps in dry‐milled g‐As2Se3 with defect‐specific positron lifetime of 0.352 ns, corresponding to diatomic/triatomic vacancies in g‐As‐Se matrix. POLYM. ENG. SCI., 59:2438–2442, 2019. © 2019 Society of Plastics Engineers 相似文献
23.
Roman Golovchak Andrzej Kozdras Oleh Shpotyuk Sergey Kozyukhin Jean-Marc Saiter 《Journal of Materials Science》2009,44(15):3962-3967
Effect of long-term physical ageing (~18–21 years) in vitreous germanium selenides is studied using differential scanning
calorimetry method. It is compared with short-term physical ageing observed in these glasses earlier. Low compositional limit
of the non-ageing ability determined using old samples coincides with the onset of reversibility window obtained using short-term
aged samples of Ge–Se system by temperature modulated differential scanning calorimetry technique. 相似文献
24.
Iryna Pohrelyuk Oleh Tkachuk Roman Proskurnyak Jan Guspiel Ewa Beltowska‐Lehman Jerzy Morgiel 《工业材料与腐蚀》2019,70(12):2320-2325
The corrosion behavior of oxynitrided Ti–6Al–4V alloy was investigated in the Ringer's solution (simulated body fluid) at a temperature of 37°C. The oxynitriding of the alloy was carried out by leaking controlled oxygen‐containing medium into the reaction chamber at the final stage of the nitride formation. It was determined that oxynitriding improved corrosion resistance of Ti–6Al–4V alloy as it provided lower corrosion current density by 1.3–1.5 times and higher corrosion potential. In this paper, we analyzed that the resistance of the double layer had increased with the increase of the oxygen content in titanium oxynitride. Its value was higher compared with untreated alloy, indicating higher corrosion resistance of the oxynitrided one. 相似文献
25.
Oleh Smutok Maria Karkovska Tetiana Prokopiv Taras Kavetskyy Wladimir Sibirnyj Mykhailo Gonchar 《Yeast (Chichester, England)》2019,36(5):341-348
During the recent decades, a lot of data about the significance of D-lactate determination in food technology and quality control have been accumulated. Nowadays, the development of new methods for the determination of D-lactate is very relevant, especially with regard to biosensors. To construct a D-lactate-selective biosensor, we suggest using the mitochondria of recombinant yeast cells of Ogataea (Hansenula) polymorpha “tr6” (gcr1 catX/Δcyb2, prAOX_DLDH) overproducing D-lactate: cytochrome c-oxidoreductase (DLDH, EC 1.1.2.4) and lacking an L-lactate-specific enzyme (flavocytochrome b2, E.C. 1.1.2.3). The usage of the pure enzyme is problematic due to the complexity of its isolation and stabilization because of the intramembranous localization of DLDH. The enzyme catalyzes D-lactate oxidation to pyruvate coupled with ferricytochrome c reduction to ferrocytochrome c. The constructed biosensor is characterized by high sensitivity (18.5 А·М−1·m−2), a low detection limit (3 μM of D-lactate), wide linear ranges, good selectivity, and sufficient stability. The real samples' analysis of D-lactate in dairy products was performed, and high correlation of the obtained results with the reference approach (0.7 < r < 1) and literature data was demonstrated. 相似文献
26.
Abraham S. Moses Leena Kadam Anna St Lorenz Maureen K. Baldwin Terry Morgan Jessica Hebert Youngrong Park Hyelim Lee Ananiya A. Demessie Tetiana Korzun Babak Mamnoon Adam W. G. Alani Oleh Taratula Leslie Myatt Olena R. Taratula 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(2):2202343
Ectopic pregnancy (EP) is the leading cause of maternity-related death in the first trimester of pregnancy. Approximately 98% of ectopic implantations occur in the fallopian tube, and expedient management is crucial for preventing hemorrhage and maternal death in the event of tubal rupture. Current ultrasound strategies misdiagnose EP in up to 40% of cases, and the failure rate of methotrexate treatment for confirmed EP exceeds 10%. Here the first theranostic strategy for potential management of EP is reported using a near-infrared naphthalocyanine dye encapsulated within polymeric nanoparticles. These nanoparticles preferentially accumulate in the developing murine placenta within 24 h following systemic administration, and enable visualization of implantation sites at various gestational stages via fluorescence and photoacoustic imaging. These nanoparticles do not traverse the placental barrier to the fetus or impact fetal development. However, excitation of nanoparticles localized in specific placentas with focused NIR light generates heat (>43 °C) sufficient for disruption of placental function, resulting in the demise of targeted fetuses with no effect on adjacent fetuses. This novel approach would enable diagnostic confirmation of EP when current imaging strategies are unsuccessful, and elimination of EP could subsequently be achieved using the same nano-agent to generate localized hyperthermia resulting in targeted placental impairment. 相似文献
27.
Carolin Harkort Dennis Kudlacik Natalia E. Kopteva Dmitri R. Yakovlev Marek Karzel Erik Kirstein Oleh Hordiichuk Maksym V. Kovalenko Manfred Bayer 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(32):2300988
The class of Ruddlesden–Popper type (PEA)2PbI4 perovskites comprises 2D structures whose optical properties are determined by excitons with a large binding energy of about 260 meV. It complements the family of other 2D semiconductor materials by having the band structure typical for lead halide perovskites, that can be considered as inverted compared to conventional III–V and II–VI semiconductors. Accordingly, novel spin phenomena can be expected for them. Spin-flip Raman scattering is used here to measure the Zeeman splitting of electrons and holes in a magnetic field up to 10 T. From the recorded data, the electron and hole Landé factors (g-factors) are evaluated, their signs are determined, and their anisotropies are measured. The electron g-factor value changes from +2.11 out-of-plane to +2.50 in-plane, while the hole g-factor ranges between -0.13 and -0.51. The spin flips of the resident carriers are arranged via their interaction with photogenerated excitons. Also the double spin-flip process, where a resident electron and a resident hole interact with the same exciton, is observed showing a cumulative Raman shift. Dynamic nuclear spin polarization induced by spin-polarized holes is detected in corresponding changes of the hole Zeeman splitting. An Overhauser field of the polarized nuclei acting on the holes as large as 0.6 T can be achieved. 相似文献
28.
Nico Jurtz Harald Kruggel-Emden Oleh Baran Ravindra Aglave Ray Cocco Matthias Kraume 《化学工程与技术》2020,43(10):1959-1970
The accuracy of coarse-grained discrete element method (CGDEM) relies on appropriate scaling rules for contact and fluid-particle interaction forces. For fluidized bed applications, different scaling rules are used and compared with DEM results. The results indicated that in terms of averaged values as mean particle position and voidage profile, the coupling of computational fluid dynamics and CGDEM leads to accurate results for low scaling factors. Regarding the particle dynamics, the approach leads to an underestimation of RMS values of particle position indicating a loss of particle dynamics in the system due to coarse graining. The impact of cell cluster size on drag force calculation is studied. The use of energy minimization multiscale drag correction is investigated, and a reduced mesh dependency and good accuracy are observed. 相似文献
29.
Abraham S. Moses Olena R. Taratula Hyelim Lee Fangzhou Luo Tanner Grenz Tetiana Korzun Anna St Lorenz Fahad Y. Sabei Shay Bracha Adam W. G. Alani Ov D. Slayden Oleh Taratula 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(18)
Endometriosis is a painful disorder where endometrium‐like tissue forms lesions outside of the uterine cavity. Intraoperative identification and removal of these lesions are difficult. This study presents a nanoplatform that concurrently delineates and ablates endometriosis tissues using real‐time near‐infrared (NIR) fluorescence and photothermal therapy (PTT). The nanoplatform consists of a dye, silicon naphthalocyanine (SiNc), capable of both NIR fluorescence imaging and PTT, and a polymeric nanoparticle as a SiNc carrier to endometriosis tissue following systemic administration. To achieve high contrast during fluorescence imaging of endometriotic lesions, nanoparticles are constructed to be non‐fluorescent prior to internalization by endometriosis cells. In vitro studies confirm that these nanoparticles activate the fluorescence signal following internalization in macaque endometrial stromal cells and ablate them by increasing cellular temperature to 53 °C upon interaction with NIR light. To demonstrate in vivo efficiency of the nanoparticles, biopsies of endometrium and endometriosis from rhesus macaques are transplanted into immunodeficient mice. Imaging with the intraoperative Fluobeam 800 system reveals that 24 h following intravenous injection, nanoparticles efficiently accumulate in, and demarcate, endometriotic grafts with fluorescence. Finally, the nanoparticles increase the temperature of endometriotic grafts up to 47 °C upon exposure to NIR light, completely eradicating them after a single treatment. 相似文献
30.
Yaroslav Shpotyuk Pavlo Demchenko Zdenka Bujňáková Peter Baláž Catherine Boussard-Pledel Bruno Bureau Oleh Shpotyuk 《Journal of the American Ceramic Society》2020,103(3):1631-1646
Effect of high-energy mechanical milling on glassy AsxSe100 − x (5 ≤ x ≤ 75) is recognized with X-ray powder diffraction analysis applied to their diffuse halos ascribed to intermediate—and extended-range structural ordering, which are revealed respectively in the first sharp diffraction peak (FSDP) and principal diffraction peak (PDP). Straightforward interpretation of the results is developed within modified microcrystalline approach, treating diffuse halos as superposition of broadened Bragg-diffraction reflexes from remnants of inter-planar correlations, supplemented by inter-atomic Ehrenfest-diffraction reflexes from most prominent inter-atomic and inter-molecular correlations between cage-like molecules (such As4Se4 and/or As4Se3). Milling is shown to be ineffective in glassy arsenoselenides near Se (x < 20), while causing increase in the FSDP width for glasses with 20 ≤ x ≤ 40 due to destroyed inter-planar ordering. Remnants of cage-like molecules in over-stoichiometric As-rich AsxSe100 − x glasses (40 ≤ x ≤ 75) disappear under milling, promoting formation of higher polymerized structural network. This milling-driven reamorphization results in a drastic increase in the FSDP position and fragmentation impact on the correlation length of the FSDP-responsible entities. Breakdown in intermediate-range ordering in these glasses is accompanied by changes in their extended-range ordering revealed in high-angular shift and broadening of the PDP. This effect is concomitant with the disappearance of distant inter-atomic correlations between quasi-crystalline planes in the milled arsenoselenide glasses at a cost of prolonged correlations dominating in their extended-range ordering. 相似文献