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showing 10 items of 18693 documents
Józef Wacław Dąbrowski (1797–1862). Wołynianin w armii Królestwa Polskiego
2021
W artykule, w oparciu o nieznane i tym samym niewykorzystywane dotąd przez historyków wspomnienia, przedstawione zostały dzieciństwo i młodość Józefa Wacława Dąbrowskiego, oficera wojska Królestwa Polskiego, dowódcę w randze kapitana i majora oddziałów powstańczych jesienią 1830 – latem 1831 r. Koleje jego losów i kariera wojskowa są tak typowe, jak i odbiegające od znanych i omawianych w literaturze przedmiotu schematów. Typowe, gdyż dzięki wywodzeniu się z kręgów średnio zamożnego ziemiaństwa rozpoczął służbę wojskową od stopnia kadeta, aby przed upływem roku awansować na podchorążego i uzyskać skierowanie do szkoły podchorążych, stanowiącej niezbędny etap służby potrzebny do awansu ofice…
Satvara izstrāde vienotai lietotāja ievades klienta un servera puses validācijai
2016
Lietotāja ievades validācija ir pašsaprotams process jebkurā nopietnā sistēmā. Slikti dati un izvairīšanās no to apstrādes var novest pie drošības riskiem, negaidītas sistēmas darbības vai sliktas pieredzes lietojot sistēmu. Parasti sistēmām servera puses un klienta puses validācijas tiek veidotas atsevišķi, taču uzdevumi bieži vien pārklājas. Kā bakalaura darba mērķis tika izvirzīts izpētīt klienta un servera puses validācijas risinājumus, atrast kopīgās raksturīpašības un izveidot sistēmu, kas ļauj vienuviet pārvaldīt izmaiņas, nodrošināt kļūdu ziņojumu tulkojumus, neatkārtot darbības, kas jau veiktas citā solī. Bakalaura darbā izvirzītā hipotēze – vienota satvara izstrāde klienta un serv…
Acoustic vibrations of monoclinic zirconia nanocrystals
2011
International audience; Polarized low-frequency Raman spectra originating from confined acoustic vibrations are reported for monoclinic ZrO2 nanoparticles with a narrow size distribution synthesized from a continuous supercritical water process. The monoclinic lattice structure is taken into account for the interpretation of the spectra by comparing with isotropic and anisotropic continuum elasticity calculations for monodomain nanocrystals. The various mechanisms leading to the broadening of the Raman peaks are discussed. We demonstrate that an accurate determination of the size distribution of the nanoparticles is possible using the Raman peak due to the fundamental breathing vibration wh…
Comparative Study on Micromechanical Properties of ZnO:Ga and ZnO:In Luminiscent Ceramics
2021
The research has been supported by the Project ERANET RUS_ST#2017-051(Latvia) and #18-52-76002 (Russia). The Institute of Solid State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Framework, Program H2020-WIDESPREAD-01-2016-2017-Teaming Phase 2 under grant agreement No. 739508, project CAMART2.
Evaluation of nano/submicro pores in suspension plasma sprayed YSZ coatings
2019
Abstract Nano-submicro pores could considerably influence the coating performances and thus should be properly designed for the intended applications. However, it is challenging to characterize accurately such small pores in coatings. In this study, YSZ coatings were firstly manufactured by suspension plasma spray (SPS) and the nano-submicro pores in as-prepared coatings were investigated using Ultra-small-angle X-ray scattering (USAXS). Afterwards, a multivariate analysis on the effect of five different process parameters was carried out. The two main results showed that: 1) the nano-submicro pores content in coatings has a negative correlation with suspension mass load and powder size, an…
Current Spreading Length and Injection Efficiency in ZnO/GaN-Based Light-Emitting Diodes
2019
We report on carrier injection features in light-emitting diodes (LEDs) based on nonintentionally doped-ZnO/p-GaN heterostructures. These LEDs consist of a ZnO layer grown by chemical-bath deposition (CBD) onto a p-GaN template without using any seed layer. The ZnO layer (~1- $\mu \text{m}$ thickness) consists of a dense collection of partially coalesced ZnO nanorods, organized in wurtzite phase with marked vertical orientation, whose density depends on the concentration of the solution during the CBD process. Due to the limited conductivity of the p-GaN layer, the recombination in the n-region is strongly dependent on the spreading length of the holes, ${L}_{h}$ , coming from the p-contact…
Marginal and internal fit evaluation of conventional metal-ceramic versus zirconia CAD/CAM crowns
2019
Background The purpose of this in vivo study was to compare the marginal and internal gap widths of monolithic zirconia crowns fabricated by CAD/CAM technique and metal-ceramic crowns fabricated by conventional technique. Material and methods 10 participants needing a single restoration were selected. Zirconia crowns using CAD/CAM technology (Group A) (n=10) and metal-ceramic crowns (Group B) (n=10) using lost wax casting technique were fabricated for each selected tooth. The marginal and internal gaps of crowns were recorded using a replica technique with light body silicone material stabilized with a regular set putty. Each replica was sectioned buccolingually and mesiodistally and then e…
On the solution of a parabolic PDE involving a gas flow through a semi-infinite porous medium
2021
Abstract Taking as start point the parabolic partial differential equation with the respective initial and boundary conditions, the present research focuses onto the flow of a sample of waste-water derived from a standard/conventional dyeing process. In terms of a highly prioritized concern, meaning environment decontamination and protection, in order to remove the dyes from the waste waters, photocatalyses like ZnO or TiO2 nanoparticles were formulated, due to their high surface energy which makes them extremely reactive and attractive. According to the basics of ideal fluid, the key point is the gas flow through an ideal porous pipe consisting of nanoparticles bound one to each other, for…
Formation of translucent nanostructured zirconia ceramics
2021
Abstract In this work the mechanisms that affect the optical transparency of nanostructured translucent ZrO2 ceramics are studied. The translucent ceramic samples were obtained from a low agglomeration nanosized powder at low pressure and low temperature sintering. Even low pressures cause structural changes and defect creation in the nanocrystals. Annealing was used to study the grain formation, structure and impact of defects. Significant changes in translucency were observed with increase in pore size. In order to further understand the defect creation, the obtained ceramics were doped with Er3+ ions and studied optically. Photoluminescence studies revealed a change in the ratio of green…
Measurement of the activation energies of oxygen ion diffusion in yttria stabilized zirconia by flicker noise spectroscopy
2019
The low-frequency noise in a nanometer-sized virtual memristor consisting of a contact of a conductive atomic force microscope (CAFM) probe to an yttria stabilized zirconia (YSZ) thin film deposited on a conductive substrate is investigated. YSZ is a promising material for the memristor application since it is featured by high oxygen ion mobility, and the oxygen vacancy concentration in YSZ can be controlled by varying the molar fraction of the stabilizing yttrium oxide. Due to the low diameter of the CAFM probe contact to the YSZ film (similar to 10nm), we are able to measure the electric current flowing through an individual filament both in the low resistive state (LRS) and in the high r…