Utilization of Extrinsic Fabry-Perot Interferometers with Spectral Interferometric Interrogation for Microdisplacement Measurement

The paper presents a number of signal processing approaches for the spectral interferometric interrogation of extrinsic Fabry-Perot interferometers (EFPIs). The analysis of attainable microdisplacement resolution is performed and the analytical equations describing the dependence of resolution on parameters of the interrogation setup are derived. The efficiency of the proposed signal processing approaches and the validity of analytical derivations are supported by experiments. The proposed approaches allow the interrogation of up to four multiplexed sensors with attained resolution between 30 pm and 80 pm, up to three times improvement of microdisplacement resolution of a single sensor by means of using the reference interferometer and noise-compensating approach, and ability to register signals with frequencies up to 1 kHz in the case of 1 Hz spectrum acquisition rate. The proposed approaches can be used for various applications, including biomedical, industrial inspection, and others, amongst the microdisplacement measurement.     

Dialog-Based Calculation of Dimensional Relations between Machine Parts

We consider computer software for automated calculation of the dimensional relations of machines in terms of the rated values and tolerances, in the light of the selected method for ensuring precision.     

Some features of thermophysical properties of γ‐Gd2S3 ceramics based on real structure

The heat capacity C_p, thermal diffusivity χ_T, and lattice thermal conductivity κ_latt of ceramic solid solutions of sesquisulfides Gd_3‐xV_Gd,xS₄ (0 < x < 0.33) in the temperature range 300‐700 K has been studied. Changing the real structure, namely the concentrations of vacancies (N_V) and deformation (N_Dc) centers of polycrystals, significantly decreases κ_latt. A deviation of composition from the stoichiometry 2:3 is accompanied by an increase in the specific area of the crystallite boundaries per unit volume, and, hence, the concentration of deformation centers D_C increases. This observation was confirmed by examining the short‐range order disturbance of the lattice and symmetry environment of the Gd³⁺ and S^2? environment by Raman spectroscopy and the magnetic susceptibility Faraday method. Therefore the thermal diffusivity of gadolinium sesquisulfide is reduced because of the mean free path of phonons decrease. As a result, the thermal conductivity of the polycrystalline samples is reduced by 10%.     

Carbon Nanoparticles as Versatile Auxiliary Components of Perovskite-Based Optoelectronic Devices

Metal halide perovskite-based optoelectronics has experienced an unprecedented development in the last decade, while further improvements of efficiency, stability, and economic gains of such devices require novel engineering concepts. The use of carbon nanoparticles as versatile auxiliary components of perovskite-based optoelectronic devices is one strategy that offers several advantages in this respect. In this review, first, a brief introduction is offered on metal halide perovskites and on the major performance characteristics of related optoelectronic devices. Then, the versatility and merits of different kinds of carbon nanoparticles, such as graphene quantum dots and carbon dots, are discussed. The tunability of their electronic properties is focused upon, their interactions with perovskite components are analyzed, and different strategies of their implementation in optoelectronic devices are introduced, which include solar cells, light-emitting diodes, luminescent solar concentrators, and photodetectors. It is shown how carbon nanoparticles influence charge carriers extraction and transport, promote perovskite crystallization, allow for efficient passivation, block ion migration, suppress hysteresis, enhance their environmental stability, and thus improve the performance of perovskite-based optoelectronic devices.     

Energy Level Modification with Carbon Dot Interlayers Enables Efficient Perovskite Solar Cells and Quantum Dot Based Light‐Emitting Diodes

Controlling the transport and minimizing charge carrier trapping at interfaces is crucial for the performance of various optoelectronic devices. Here, how electronic properties of stable, abundant, and easy‐to‐synthesized carbon dots (CDs) are controlled via the surface chemistry through a chosen ratio of their precursors citric acid and ethylenediamine are demonstrated. This allows to adjust the work function of indium tin oxide (ITO) films over the broad range of 1.57 eV, through deposition of thin CD layers. CD modifiers with abundant amine groups reduce the ITO work function from 4.64 to 3.42 eV, while those with abundant carboxyl groups increase it to 4.99 eV. Using CDs to modify interfaces between metal oxide (SnO₂ and ZnO) films and active layers of solar cells and light‐emitting diodes (LEDs) allows to significantly improve their performance. Power conversion efficiency of CH₃NH₃PbI₃ perovskite solar cells increases from 17.3% to 19.5%; the external quantum efficiency of CsPbI₃ perovskite quantum dot LEDs increases from 4.8% to 10.3%; and that of CdSe/ZnS quantum dot LEDs increases from 8.1% to 21.9%. As CD films are easily fabricated in air by solution processing, the approach paves the way to a simplified manufacturing of large‐area and low‐cost optoelectronic devices.     

ManyLands: A Journey Across 4D Phase Space of Trajectories

Mathematical models of ordinary differential equations are used to describe and understand biological phenomena. These models are dynamical systems that often describe the time evolution of more than three variables, i.e., their dynamics take place in a multi‐dimensional space, called the phase space. Currently, mathematical domain scientists use plots of typical trajectories in the phase space to analyze the qualitative behavior of dynamical systems. These plots are called phase portraits and they perform well for 2D and 3D dynamical systems. However, for 4D, the visual exploration of trajectories becomes challenging, as simple subspace juxtaposition is not sufficient. We propose ManyLands to support mathematical domain scientists in analyzing 4D models of biological systems. By describing the subspaces as Lands, we accompany domain scientists along a continuous journey through 4D HyperLand, 3D SpaceLand, and 2D FlatLand, using seamless transitions. The Lands are also linked to 1D TimeLines. We offer an additional dissected view of trajectories that relies on small‐multiple compass‐alike pictograms for easy navigation across subspaces and trajectory segments of interest. We show three use cases of 4D dynamical systems from cell biology and biochemistry. An informal evaluation with mathematical experts confirmed that ManyLands helps them to visualize and analyze complex 4D dynamics, while facilitating mathematical experiments and simulations.     

Size-dependent structural and magnetic properties of chemically synthesized Co-Ni-Ga nanoparticles

Phase transitions and magnetic properties of shape-memory materials can be tailored by tuning the size of the constituent materials,such as nanoparticles.However,owing to the lack of suitable synthetic methods for size-controlled Heusler nanoparticles,there is no report on the size dependence of their properties and functionalities.In this contribution,we present the first chemical synthesis of size-selected Co-Ni-Ga Heusler nanoparticles.We also report the structure and magnetic properties of the biphasic Co-Ni-Ga nanoparticles with sizes in the range of 30-84 nm,prepared by a SBA-15 nanoporous silicatemplated approach.The particle sizes could be readily tuned by controlling the loading and concentration of the precursors.The fractions and crystallite sizes of each phase of the Co-Ni-Ga nanoparticles are closely related to their particle size.Enhanced magnetization and decreased coercivity are observed with increasing partide size.The Curie temperature (Tc) of the Co-Ni-Ga nanoparticles also depends on their size.The 84 nm-sized particles exhibit the highest Tc (≈ 1,174 K) among all known Heusler compounds.The very high Curie temperatures of the Co-Ni-Ga nanoparticles render them promising candidates for application in high-temperature shape memory alloy-based devices.     

A Sol–Gel Derived CuOx/Al2O3–ZrO2 Catalyst for the Selective Reduction of NO by Propane in the Presence of Excess Oxygen

Copper catalysts supported on alumina-doped zirconia were prepared by sol–gel processing followed by supercritical drying or aging in the mother solution at 100°C. After drying and calcination, the catalyst supports were impregnated with a copper(II) nitrate aqueous solution by the incipient wetness method to achieve a Cu loading of about 2%. The samples showed 90% NO conversion at 350–400°C. The catalytic performance of these systems appears to be determined by the degree of clustering of copper cations as probed by FTIR spectroscopy of adsorbed CO.     

The Comprehensive Upgrading of an MИ-1201 Mass Spectrometer

The set of operations used to upgrade an MИ-1201 magnetic sector mass spectrometer is described. The upgrading consisted of automating the recording system, developing the software, and modifying the vacuum system. The modified instrument was tested by analyzing both CO₂ samples with a natural isotopic composition of oxygen and water samples enriched with the ¹⁸O isotope. The reproducibility of results from measuring the ¹⁶O concentration was 0.005%. For water samples enriched with ¹⁸O, the experimental results correlate with the predetermined isotopic concentrations.__________Translated from Pribory i Tekhnika Eksperimenta, No. 3, 2005, pp. 55–61.Original Russian Text Copyright © 2005 by Ivanov, Moiseeva, Trofimov, Dryannov, Aleksei Sysoev, Aleksandr Sysoev.     

A simple imaging‐based technique for quantifying haze and transmittance of materials

We present a simple technique for measuring haze and transmittance of materials that uses inexpensive and virtually ubiquitous hardware, and is based on photographic imaging of at least partially transparent samples backlit through a “knife‐edge” array mask. Its performance is tested for a series of injection‐molded polyethylene plaques containing a varied fraction of a clarifying agent, as well as commercially available ASTM D1003 haze standards. The results show excellent agreement with those obtained using a conventional haze meter adhering to the ASTM D1003 standard and, moreover, are specifically indicative of the overall contact haze—a desirable feature for characterization of, for instance, commodity plastics for packaging applications. Notably, the quantification of haze is based explicitly on the reduction of perceived image quality of objects viewed through a material sample and, hence, quantifies haze in a more practically useful way compared with the, arguably, more arbitrary ASTM definition. The demonstrated technique can be further used to extract more sophisticated, local information on the microstructure and optical properties, which cannot be obtained with a conventional haze meter. Its potential for being standardized, as well as additional modifications that can enable improved performance, are also discussed. POLYM. ENG. SCI., 58:345–352, 2018. © 2017 Society of Plastics Engineers