Ag and N acceptors in ZnO: ab initio study of acceptor pairing, doping efficiency, and the role of hydrogen

Efficiency of ZnO doping with Ag and N shallow acceptors, which substitute respectively cations and anions, was investigated. First principles calculations indicate a strong tendency towards formation of nearest neighbor Ag-N pairs and N-Ag-N triangles. Binding of acceptors stems from the formation of quasi-molecular bonds between dopants, and has a universal character in semiconductors. The pairing increases energy levels of impurities, and thus lowers doping efficiency. In the presence of donors, pairing is weaker or even forbidden. However, hydrogen has a tendency to form clusters with Ag and N, which favors the Ag-N aggregation and lowers the acceptor levels of such complexes.Comment: 10 pages, 4 figure

Імпліцитна оцінка у фокусі сучасних дискурсивних досліджень

У статті розглянуто поняття імпліцитної оцінки через призму сучасних досліджень лінгвістики. Велика увага приділяється поняттю імпліцитності, що охоплює різні мовознавчі аспекти, виявлено декілька підходів тлумачення сутності мовленнєвого імпліціювання, кожний з яких має як об’єкт дослідження різні аспекти багатопланового явища опосередкування, які, таким чином, доповнюють один одного. (The article deals with the notion of implicit evaluation through the prism of contemporary linguistics researches. Much attention is paid to the notion of implicitness which covers various aspects of linguistics. Several approaches of interpretation of the notion implicitness are also revealed, which complement each other and therefore help to formulate the definition of implicit evaluation.

Electronic structure and Jahn-Teller effect in GaN:Mn and ZnS:Cr

We present an ab-initio and analytical study of the Jahn-Teller effect in two diluted magnetic semiconductors (DMS) with d4 impurities, namely Mn-doped GaN and Cr-doped ZnS. We show that only the combined treatment of Jahn-Teller distortion and strong electron correlation in the 3d shell may lead to the correct insulating electronic structure. Using the LSDA+U approach we obtain the Jahn-Teller energy gain in reasonable agreement with the available experimental data. The ab-initio results are completed by a more phenomenological ligand field theory.Comment: 15 pages, 5 figure

Creative Personality of an Editor as a Phenomenon in the Context of Professional and Spiritual Evolution

Розглянуто поняття творчої особистості редактора, його ролі у діяльності видавництва, описано зв’язки між творчістю, особистісним зростом і професійністю в контексті духовного розвитку, окреслено два основних напрямки розвитку особистості, виділено основні фактори, поєднання яких відрізняє творчу особистість редактора поміж інших редакторів. Creative Personality of an Editor as a Concept is analyzed. Editor’s Part in Publishing and Editing Activities as well as Interrelationship between Creative Activities, Personal Growth and Professional Level are Discussed in the Context of Spiritual Development. Two main directions of Personality Development are Two Basic Factors are Singled out which in their Combination Differentiate Editor’s Creative Personality among Other Editors

Supernatants derived from chemotherapy-treated cancer cell lines can modify angiogenesis

BACKGROUND: There is evidence that tumours produce substances such as cytokines and microvesicular bodies bearing bioactive molecules, which support the carcinogenic process. Furthermore, chemotherapy has also been shown to modify these exudates and in doing so, neutralise their tumourigenic influence. METHODS: In the current study, we have investigated the effect of chemotherapy agents on modifying the cytokine profile and microvesicular cargo of supernatants derived from cancer cell lines. In addition, we have explored the effect of these tumour-derived supernatants on angiogenesis, and how chemotherapy can alter the supernatants rendering them less pro-angiogenic. RESULTS: Herein, we show that supernatants contain a rich cocktail of cytokines, a number of which are potent modulators of angiogenesis. They also contain microvesicular bodies containing RNA transcripts that code for proteins involved in transcription, immune modulation and angiogenesis. These supernatants altered intracellular signalling molecules in endothelial cells and significantly enhanced their tubulogenic character; however, this was severely compromised when supernatants from tumours treated with chemotherapy was used instead. CONCLUSION: This study suggests tumour exudates and bioactive material from tumours can influence cellular functions, and that treatment with some chemotherapy can serve to negate these pro-tumourigenic processes

Risk aversion is at the heart of the cyber response dilemma

Cybersecurity en cybergovernanc

Evidence for two-electron processes in the mutual neutralization of O- with O+ and N+ at Subthermal Collision Energies

We have measured total absolute cross sections for the Mutual Neutralization (MN) of O- with O+/N+. A fine resolution (of about 50 meV) in the kinetic energy spectra of the product neutral atoms allows unique identification of the atomic states participating in the mutual neutralization process. Cross sections and branching ratios have also been calculated down to 1 meV center-of-mass collision energy for these two systems with a multi-channel Landau-Zener model and an asymptotic method for the ionic-covalent coupling matrix elements. The importance of two-electron processes in one-electron transfer is demonstrated by the dominant contribution of a core-excited configuration of the nitrogen atom in N+ + O- collisions. This effect is partially accounted for by introducing configuration mixing in the evaluation of coupling matrix elements.Comment: 5 pages, 4 figure

Faults Affecting Energy-Harvesting Circuits of Self-Powered Wireless Sensors and Their Possible Concurrent Detection

We analyze the effects of faults on an energy-harvesting circuit (EHC) providing power to a wireless biomedical multisensor node. We show that such faults may prevent the EHC from producing the power supply voltage level required by the multisensor node. Then, we propose a low-cost (in terms of power consumption and area overhead) additional circuit monitoring the voltage level produced by the EHC continuously, and concurrently with the normal operation of the device. Such a monitor gives an error indication if the generated voltage falls below the minimum value required by the sensor node to operate correctly, thus allowing the activation of proper recovery actions to guarantee system fault tolerance. The proposed monitor is self-checking with regard to the internal faults that can occur during its in-field operation, thus providing an error signal when affected by faults itself