Spectroscopy of solid-solution transparent sesquioxide laser ceramic Tm:LuYO3

We report on a detailed spectroscopic study of a Tm3+-doped transparent sesquioxide ceramic based on a solid-solution (lutetia – yttria, LuYO3) composition. The ceramic was fabricated using commercial oxide powders by hot isostatic pressing at 1600°C for 3 h at 190 MPa argon pressure. The most intense Raman peak in Tm:LuYO3 at 385.4 cm−1 takes an intermediate position between those for the parent compounds and is notably broadened (linewidth: 12.8 cm−1). The transition intensities of Tm3+ ions were calculated using the Judd-Ofelt theory; the intensity parameters are W2 = 2.537, W4 = 1.156 and W6 = 0.939 [1020 cm2]. For the 3F4 → 3H6 transition, the stimulated-emission cross-section amounts to 0.27 × 10−20 cm2 at 2059nm and the reabsorption-free luminescence lifetime is 3.47 ms (the 3F4 radiative lifetime is 3.85 ± 0.1 ms). The Tm3+ ions in the ceramic exhibit long-wave multiphonon-assisted emission extending up to at least 2.35 µm; a phonon sideband at 2.23 µm is observed and explained by coupling between electronic transitions and the dominant Raman mode of the sesquioxides. Low temperature (12 K) spectroscopy reveals a significant inhomogeneous spectral broadening confirming formation of a substitutional solid-solution. The mixed ceramic is promising for ultrashort pulse generation at >2 µm

Stakeholder cooperation to overcome challenges in orphan medicine development: The example of Duchenne muscular dystrophy

Duchenne muscular dystrophy is a rare, progressive, muscle-wasting disease leading to severe disability and premature death. Treatment is currently symptomatic, but several experimental therapies are in development. Implemented care standards, validated outcome measures correlating with clinical benefit, and comprehensive information about the natural history of the disease are essential for regulatory approval of any treatment. However, for Duchenne muscular dystrophy and other rare diseases, these requirements are not always in place when potential therapies enter the clinical trial phase. A cooperative effort of stakeholders in Duchenne muscular dystrophy-including representatives from patients' groups, academia, industry, and regulatory agencies-is aimed at addressing this shortfall by identifying strategies to overcome challenges, developing the tools needed, and collecting relevant data. An open and constructive dialogue among European stakeholders has positively affected development of treatments for Duchenne muscular dystrophy; this approach could serve as a paradigm for development of treatments for rare diseases in general

Modern World-View of Culture and Web-Space

В статье рассматривается информационный подход, в рамках которого происходит возрождение интереса к культурной картине мира в условиях формирования Web-пространства, что значительно отличает современную картину мира культуры от классических картин мира прошлого. Кроме того, по причине сложности и неоднозначности современной социокультурной ситуации проекции культурной картины должны быть разные, чтобы максимально рассмотреть ее существенные стороны и разнообразие проявления.In article, it is considered, the information approach in which frameworks, there is a revival of interest to cultural world-view conditions of formation of Web-space it considerably distinguishes a modern world-view of culture, from a classical world-view of the past. Besides, because of complexity and ambiguity of a modern social and cultural situation, a projection of a cultural world-view should be different as much as possible to consider its essential parties and a variety of display

A method for determination of mass-exchange and capacitive characteristics of absorbers for life support systems

We describe a method for determining mass-exchange and capacitance characteristics of chemisorbents of carbon dioxide. Through a cartridge equipped with a chemosorbent, a gas-air mixture is blown continuously from a sealed container of a small volume into which the impurity of carbon dioxide is continuously introduced. The gas-air mixture, which has been purified from the impurity, is again introduced into the tank. The concentration of carbon dioxide in a sealed volume is monitored by means of the gas analyzer; the effective mass transfer coefficient and the maximum capacity of the chemisorbent for carbon dioxide are calculated from the obtained data

A method for determination of mass-exchange and capacitive characteristics of absorbers for life support systems

We describe a method for determining mass-exchange and capacitance characteristics of chemisorbents of carbon dioxide. Through a cartridge equipped with a chemosorbent, a gas-air mixture is blown continuously from a sealed container of a small volume into which the impurity of carbon dioxide is continuously introduced. The gas-air mixture, which has been purified from the impurity, is again introduced into the tank. The concentration of carbon dioxide in a sealed volume is monitored by means of the gas analyzer; the effective mass transfer coefficient and the maximum capacity of the chemisorbent for carbon dioxide are calculated from the obtained data

Modern World-View of Culture and Web-Space

В статье рассматривается информационный подход, в рамках которого происходит возрождение интереса к культурной картине мира в условиях формирования Web-пространства, что значительно отличает современную картину мира культуры от классических картин мира прошлого. Кроме того, по причине сложности и неоднозначности современной социокультурной ситуации проекции культурной картины должны быть разные, чтобы максимально рассмотреть ее существенные стороны и разнообразие проявления.In article, it is considered, the information approach in which frameworks, there is a revival of interest to cultural world-view conditions of formation of Web-space it considerably distinguishes a modern world-view of culture, from a classical world-view of the past. Besides, because of complexity and ambiguity of a modern social and cultural situation, a projection of a cultural world-view should be different as much as possible to consider its essential parties and a variety of display

Spark Plasma Sintering of Si₃N₄ Ceramics with Y₂O₃–Al₂O₃ (3%–10% wt.) as Sintering Additive

The ceramic samples fabricated by spark plasma sintering of powder mixtures based on silicon nitride (Si3N4) were investigated. The powder mixtures were made by wet chemical methods from commercial α-Si3N4 powder (the particle size 2O3-Al2O3 sintering additive (3% to 10% wt.). Sintering was carried out at the heating rate of 50 °C/min and the load of 70 MPa until the shrinkage end. The powder mixtures and ceramic samples were characterized by scanning electron microscopy and X-ray diffraction. The shrinkage of the powder mixtures during sintering was analyzed, and the activation energy of sintering was calculated according to the Young-Cutler model. The density, microhardness, and fracture toughness of the ceramic samples were also measured. All samples had high relative densities (98%–99%), Vickers microhardness 15.5–17.4 GPa, and Palmquist fracture toughness, 3.8–5.1 MPa∙m1/2. An increase in the amount of sintering additive led to a decrease in the shrinkage temperature of the powder mixtures. The amount of β-Si3N4 in the ceramics decreased monotonically with the increasing amount of sintering additive. The shrinkage rate did not decrease to zero when the maximum compaction was reached at 3% wt. of the sintering additive. On the contrary, it increased sharply due to the beginning of the Si3N4 decomposition

Thermal Conductivity of Yttria-Gadolinia Solid Solution Optical Ceramics in the Temperature Range 50–300 K

This study looked at the thermal conductivity of translucent (Y1−xGdx)2O3 (where 0 ≤ x ≤ 1) solid solution ceramics in the temperature range from 50 K to 300 K. The samples were obtained by hot pressing from high-purity nanopowders at 1600 °C, no sintering additives were used. Compositions with cubic syngony (x ≤ 0.7) and a monoclinic one (x ≥ 0.9) were investigated. Furthermore, a dense sample of cubic Gd2O3 with a LiF sintering additive was obtained and its thermal conductivity was determined (k = 11.7 W/(m K) at 300 K). It was shown that in the range of solid solution ceramic compositions 0.2 ≤ x ≤ 0.7, the thermal conductivity was practically unchanged and close to the value k ≈ 5 W/(m K) at 300 K

Hot pressing of Yb:Y2O3 laser ceramics with LiF sintering aid

International audienc

A System for the Direct Monitoring of Biological Objects in an Ecologically Balanced Zone

This article discusses a model of a robotic platform that can be used for the proximal probing of biological objects in an ecologically balanced zone. The proximal probing is for scanning deciduous and fertile parts of biological objects with a hyperspectral camera at a distance of no more than a few meters. It allows for the obtention of information about the presence of phyto-diseases of tissues and also about the degree of ripeness and other parameters of the internal quality of the fruit. In this article, we report the methods and approaches used to detect fruits in the crown of a tree and also to identify their diseases such as scab and decay with an accuracy of at least 87%. For the autonomous movement of the platform in an ecologically balanced area, visual and inertial navigation is based on a Zed 2i stereo camera. This allows for the moving of biological objects in accordance with a given route indicated on the 2D map. The analysis of the information received from this platform allows for the building of maps of the presence of phyto-deseases in an ecologically balanced zone, and decisions are promptly made regarding the implementation of technical and protective measures that ensure high-quality products