Search results for "surface"
showing 10 items of 9345 documents
Near‐IR Radiation‐Induced Attenuation of Aluminosilicate Optical Fibers
2021
The X-ray radiation-induced attenuation (RIA) growth kinetics are studied online in different single-mode aluminosilicate optical fibers in the near-IR (NIR) domain to evaluate their potential in terms of dosimetry. The optical fibers differ by Al contents, core sizes, drawing parameters, and also by a preform deposition process. The data show no dependence of the RIA on all these parameters, a positive result for the design of point or distributed radiation detectors exploiting RIA to monitor the dose. The RIA growth rate is unchanged for dose rates changing from 0.073 to 6.25 Gy(SiO2) s−1, and the RIA linearly increases with the dose up to 2 kGy(SiO2). Small but noticeable RIA changes are…
Silver Sulfide Nanoclusters and the Superatom Model
2015
The superatom model of electron-shell closings has been widely used to explain the stability of noble-metal nanoclusters of few nanometers, including thiolate-protected Au and Ag nanoclusters. The presence of core sulfur atoms in silver sulfide (Ag–S) nanoclusters renders them a class of clusters with distinctive properties as compared to typical noble-metal clusters. Here, it is natural to ask whether the superatom model is still applicable for the Ag–S nanoclusters with mixed metal and nonmetal core atoms. To address this question, we applied density functional simulations to analyze a series of Ag–S nanoclusters: Ag14S(SPh)12(PPh3)8, Ag14(SC6H3F2)12(PPh3)8, Ag70S16(SPh)34(PhCO2)4(triphos…
Mechanical and optical properties of as-grown and thermally annealed titanium dioxide from titanium tetrachloride and water by atomic layer deposition
2021
Funding Information: This work was carried out within the MECHALD project funded by Business Finland (Tekes) and is linked to the Finnish Centers of Excellence in Atomic Layer Deposition (ref. 251220) and Nuclear and Accelerator Based Physics (refs. 213503 and 251353) of the Academy of Finland. Funding Information: This work was carried out within the MECHALD project funded by Business Finland (Tekes) and is linked to the Finnish Centers of Excellence in Atomic Layer Deposition (ref. 251220 ) and Nuclear and Accelerator Based Physics (refs. 213503 and 251353 ) of the Academy of Finland. Publisher Copyright: © 2021 The use of thin-films made by atomic layer deposition (ALD) is increasing in …
Synergistic photo-release of drugs by non-linear excitation
2014
ABSTRACTNanomaterials engineered in novel multi-modular systems in which every component works in a synergistic way with others could potentially lead to a completely new type of tools for nanomedicine. The development of nanostructures able to release drugs directly within the target after a stimulus can drastically improve the therapeutics efficiency by reducing side effects. Gold nanoparticles offer one of the most suitable platforms for the development of modular nano-devices. On the one hand, their surface properties enable effective coating by peptides containing at least one cysteine, thus yielding stable and non-cytotoxic systems. On the other, their intriguing photophysics, charact…
Atomic layer deposition of AlN from AlCl3 using NH3 and Ar/NH3 plasma
2018
The atomic layer deposition (ALD) of AlN from AlCl3 was investigated using a thermal process with NH3 and a plasma-enhanced (PE)ALD process with Ar/NH3 plasma. The growth was limited in the thermal process by the low reactivity of NH3, and impractically long pulses were required to reach saturation. Despite the plasma activation, the growth per cycle in the PEALD process was lower than that in the thermal process (0.4A ° vs 0.7A ° ). However, the plasma process resulted in a lower concentration of impurities in the films compared to the thermal process. Both the thermal and plasma processes yielded crystalline films; however, the degree of crystallinity was higher in the plasma process. The…
Refractive index sensing by a silicon metasurface
2022
The availability of smart materials represents a key enabling milestone for the realization of smart sensors. In this research field, optical sensing has gained a lot of attention in various applications ranging from basic physics to chemistry and biology. Here, we exploit the non-invasive nature of light to achieve an innovative sensor based on all-optical dielectric nano-resonators arranged in a periodic fashion. The proposed sensor can measure refractive index changes up to 10(-6).
Use of digital displays and ocular surface alterations
2023
Aunque nuestra comprensión de los efectos del uso de dispositivos electrónicos sobre la superficie ocular ha aumentado considerablemente desde el inicio de siglo, varias preguntas importantes siguen sin respuesta. Asimismo, los avances tecnológicos y la aparición de nuevas formas de dispositivos digitales hacen necesaria una investigación continua. Esta tesis doctoral presenta un total de 12 estudios independientes los cuales constituyen los pilares de este trabajo (Capítulos 4-15). En primer lugar, el Capítulo 4 tuvo como objetivo evaluar la asociación entre los factores de riesgo de la enfermedad de ojo seco (EOS) y el síndrome visual informático (SVI). Se llevó a cabo una encuesta online…
Synthesis and Holographic Properties of Alkyl 2-Cyanoacetate Acceptor Fragment Containing Push – Pull Type Organic Glasses
2015
We present synthesis, optical and holographic properties of original structure organic glasses based on compounds consisting of three fragments: of N,N-bis(2-(trityloxy)ethyl)-4-vinylaniline or N,N-bis(5,5,5-triphenylpentyl)-4-vinylaniline fragments as electron donating fragment (D), 4H-pyran-4-ylidene fragment as linker(π) and of 2-(trityloxy)ethyl 2-cyanoacetate or 5,5,5-triphenylpentyl 2-cyanoacetate as acceptor (A) fragment. These push-pull (D- π-A) type molecular compounds show good solubility in non-polar solvents (CHCl3 or CH2Cl2) and neat thin films with sufficient optical qualities have been obtained by spin-coating technique. Maxima of UV–VIS absorption in dichloromethane solution…
Direct P-functionalization of azobenzene by a cationic phosphidozirconocene complex.
2016
International audience; We report that the cationic phosphidozirconocene complex [(eta(5)-C5H5)(2)Zr(PCy2)][CH3B(C6F5)(3)] (II) reacts with azobenzene, resulting in the expedient formation of Zr complex (2) bound to a tridentate PNN ligand. This reaction proceeds by a mechanism of cooperative nucleophilic substitution of hydrogen. The intermediate sigma(H) adduct (1) has been characterized by NMR spectroscopy.
An inverse problem for the minimal surface equation
2022
We use the method of higher order linearization to study an inverse boundary value problem for the minimal surface equation on a Riemannian manifold $(\mathbb{R}^n,g)$, where the metric $g$ is conformally Euclidean. In particular we show that with the knowledge of Dirichlet-to-Neumann map associated to the minimal surface equation, one can determine the Taylor series of the conformal factor $c(x)$ at $x_n=0$ up to a multiplicative constant. We show this both in the full data case and in some partial data cases.