Dushanbe, Tajikistan
Dushanbe, Tajikistan

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The dependence of beryllium, magnesium, and praseodymium additives on the temperature dependences of the Zn–55Al alloy thermophysical properties and thermodynamic functions is investigated. With the increase in the alloying additive, the values of the studied properties increase with the temperature increase whereas the Gibbs energies decrease. © 2017, Pleiades Publishing, Ltd.

Yi T.,University of California at Davis | Abdusalyamova M.N.,Academy of Sciences of Tajikistan | Makhmudov F.,Academy of Sciences of Tajikistan | Kauzlarich S.M.,University of California at Davis
Journal of Materials Chemistry | Year: 2012

A series of single crystal samples, Yb 14MnSb 11-xTe x (x ≤ 0.2), were investigated via Sn flux. The element distributions were mapped using an electron microprobe, which demonstrated inhomogeneity and limited solubility of Te in the crystals. The magnetic properties of two crystals of compositions Yb 13.80(2)Mn 1.03(1)Sb 11.11(4)Te 0.06(3) and Yb 13.82(3)Mn 1.02(1)Sb 11.02(8)Te 0.14(6) were investigated. Increasing amounts of Te increase the saturation moment of Yb 14MnSb 11-xTe x, and slightly lower the ordering temperature T C by about 1 K. This is attributed to the filling of the hole in Yb 14MnSb 11 and the reduction of the screening of the Mn 2+ d 5 electrons, resulting in a higher effective moment. Hot-pressed, fully dense pellets of Yb 13.72(3)Mn 1.08(1)Sb 11.13(6)Te 0.07(5), Yb 13.76(5)Mn 1.11(1)Sb 10.96(8)Te 0.16(8), and Yb 13.76(4)Mn 1.10(2)Sb 10.95(9)Te 0.19(7) were prepared for thermoelectric property measurements. Both Seebeck coefficient and electrical resistivity increase with increasing amount of Te as a result of decreasing carrier concentration. Increasing amounts of YbTe with increasing x could be identified in the electron microprobe. The total thermal conductivity was approximately the same for all compositions, similar to that of Yb 14MnSb 11. The figure of merit zT reaches a maximum of 1.11 for x = 0.07 at 1240 K, which is approximately 12% higher than the parent compound, Yb 14MnSb 11. © 2012 The Royal Society of Chemistry.

Agency: European Commission | Branch: FP7 | Program: CSA-CA | Phase: INCO.2013-1.2 | Award Amount: 2.23M | Year: 2013

The project aims to support the advancement of the bi-regional STI policy dialogue between the EU MS/AC and the Central Asian countries, with an explicit focus on the Societal Challenges that have been identified to be of mutual interest for the two regions, namely Climate Change, Energy and Health. In particular the project will identify actions and stakeholders and will implement innovative pilot activities to strengthen the coordination and impact of the individual actions. In terms of policy dialogue, the project will provide analytical evidence and monitoring to feed the dialogue and to support joint agenda setting. A policy mix review will be implemented along with capacity building activities with emphasis on the promotion of Innovation. More specifically, links with the EU technology platforms will be established allowing mutual learning and exchange of best practices for enhanced public-private partnerships between the two regions. In addition, support to FP contacts will be provided to strengthen their role and to adapt their functioning to the challenges of H2020. The proposed project will build on the experience of the previous projects (IncoNet EECA and IncoNet CA/SC) targeting the region and will develop synergies with the forthcoming project targeting the Eastern Partnership countries.

Shukrinov Yu.M.,Academy of Sciences of Tajikistan | Rahmonov R.,Academy of Sciences of Tajikistan
Journal of Experimental and Theoretical Physics | Year: 2012

The role of a diffusion current in the phase dynamics of a system of coupled Josephson junctions (JJs) has been analyzed. It is shown that, by studying the temporal dependences of the superconducting, quasi-particle, diffusion, and displacement currents and the dependences of average values of these currents on the total current, it is possible to explain the main features of the current-voltage characteristic (CVC) of the system. The effect of a diffusion current on the character of CVC branching in the vicinity of a critical current and in the region of hysteresis, as well as on the part of CVC branch corresponding to a parametric resonance in the system is demonstrated. A clear interpretation of the differences in the character of CVC branching in a model of capacitively coupled JJs (CCJJ model) and a model of capacitive coupling with diffusion current (CCJJ+DC model) is proposed. It is shown that a decrease in the diffusion current in a JJ leads to the switching of this junction to an oscillating state. The results of model calculations are qualitatively consistent with the experimental data. © Pleiades Publishing, Inc., 2012.

Sharopov F.S.,Academy of Sciences of Tajikistan | Setzer W.N.,University of Alabama in Huntsville
Natural Product Communications | Year: 2011

The essential oil from the aerial parts of Artemisia scoparia was obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. A total of 32 compounds were identified representing 98.0% of the total oil composition. A. scoparia oil was dominated by the diacetylenes 1-phenyl-2,4-pentadiyne (34.2%) and capillene (4.9%). Other major components were β-pinene (21.3%), methyl eugenol (5.5%), α-pinene (5.4%), myrcene (5.2%), limonene (5.0%), and (E)-β-ocimene (3.8%). The oil was tested for in-vitro cytotoxic activity against MCF-7 cells, but was inactive.

Kokhirova G.I.,Academy of Sciences of Tajikistan | Borovicka J.,Academy of Sciences of the Czech Republic
Astronomy and Astrophysics | Year: 2011

The fireball network in Tajikistan operates since 2009. Observations of the 2009 Leonid activity were carried out on November 13-21. In this period 16 Leonid fireballs were photographed. As a result of astrometric and photometric reductions, the precise data including atmospheric trajectories, velocities, orbits, light curves, and photometric masses were determined for ten fireballs. Low-resolution video spectra were obtained for six fireballs.The radiant positions during the maximum night suggest that the majority of the fireball activity was caused by the annual stream component with only minor contribution of the 1466 trail. According to their end heights, nearly half of Leonid fireballs belonged to the most fragile and weak fireball group IIIB and the rest to the slightly more dense cometary group IIIA. However, one detected Leonid belonged to the fireball group I. This is the first detection of an anomalously strong Leonid individual. Its chemical composition was not markedly different from other Leonids. © 2011 ESO.

Babadzhanov P.B.,Academy of Sciences of Tajikistan | Williams I.P.,Queen Mary, University of London | Kokhirova G.I.,Academy of Sciences of Tajikistan
Astronomy and Astrophysics | Year: 2013

A group of near-Earth asteroids (NEAs) that moved on similar orbits to each other and where the orbits could be classed as cometary were identified by searching the "Near-Earth Objects Dynamic Site" database. Six NEAs were identified, 2003HP2, 2006WX29, 2007VH189, 2007WT3, 2007WY3, and 2008UM1. The orbits were integrated back over one complete cycle in the variation of the argument of perihelion to identify times when their nodal distance was 1 AU. Theoretical meteoroids were assumed to have been released at these times on an orbit identical to those of the NEAs. The characteristics of a meteor shower that would be formed when these meteoroids hit the Earth's atmosphere were calculated. It was found that the showers produced from all six NEAs were identical and could be recognized as the nighttime χ- and δ-Scorpiids and the daytime β- and σ-Librids, the latter two being named by us. It was also found that the orbital evolution of the Scorpiids was almost identical to the orbital evolution of the six NEAs. The similarity of the orbits, the nature of the orbit as cometary and the association of the Scorpiid meteoroid stream lead us to suggest that the origin of the whole complex was the fragmentation of some unknown comet several millennia ago. © ESO, 2013.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: SPA.2012.1.1-04 | Award Amount: 2.44M | Year: 2013

SENSUM will deliver innovative methodologies and software tools for dynamic, multi-resolution monitoring of pre-disaster vulnerability and preparedness and post-disaster recovery planning and monitoring, based on current and future space-based products and a novel approach to in-situ observation for data rich and data poor countries. For this project, earthquake and landslide related vulnerability indicators are considered through test-cases in and outside Europe. The project responds to the urgent need to monitor and map time-dependent hazard and vulnerability, by triangulating space-based and in-situ data-collection, according to the type and extent of the natural hazard. The project will analyse the data needs of the end users through the three civil protection partners. A novel sampling framework will be developed that guides the in-situ data collection and integration process. Novel in-situ data collection tools (e.g. omni-directional imaging) will be included. Advanced analysis and processing of current and future space-based products will enhance the approach. Uncertainties will be fully considered. Soon-to-be-released space products such as DLR Global Urban Footprint will be validated and their integration with the proposed methodologies explored. Data needs for post-disaster recovery will be addressed within the same framework, resulting in a comprehensive methodological solution to the monitoring of time-varying indicators at multiple spatial scales throughout the disaster cycle. The consortium of 8 prominent scientific institutions and highly skilled SMEs has considerable experience in their respective fields. Many partners currently collaborate on the Global Earthquake Model Inventory Data Collection Tool (GEM IDCT). The ultimate goal is to produce a multi-resolution time varying indicator monitoring framework that applies to the whole disaster cycle. The framework is intended to become the de-facto standard for future mapping of vulnerabilities.

Sharopov F.S.,Academy of Sciences of Tajikistan | Setzer W.N.,University of Alabama in Huntsville
Records of Natural Products | Year: 2012

The essential oil from the aerial parts of Salvia sclarea L., growing wild in Tajikistan, were obtained by hydrodistillation and analyzed by gas chromatography - mass spectrometry. A total of 59 compounds were identified representing 94.2% of total oil composition. Major components of the essential oil were linalyl acetate (39.2%), linalool (12.5%), germacrene D (11.4%), α-terpineol (5.5%), geranyl acetate (3.5%), and (E)-caryophyllene (2.4%). The chemical composition, the large concentrations of linalool and linalyl acetate, and a cluster analysis based on principal components; of Tajik S. sclarea oil reveal it to be comparable to commercial S. sclarea oils.

Sharopov F.S.,Academy of Sciences of Tajikistan | Sulaimonova V.A.,Academy of Sciences of Tajikistan | Setzer W.N.,University of Alabama in Huntsville
Records of Natural Products | Year: 2012

Three samples of Artemisia absinthium were collected from two different locations in the centralsouth of Tajikistan. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. A total of 41 compounds were identified representing 72-94% of total oil compositions. The major components of A. absinthium oil were myrcene (8.6-22.7%), cis-chrysanthenyl acetate (7.7-17.9%), a dihydrochamazulene isomer (5.5-11.6%), germacrene D (2.4-8.0%), β-thujone (0.4-7.3%), linalool acetate (trace-7.0%), β-phellandrene (1.0-5.3%), and linalool (5.3-7.0%). The chemical compositions of A. absinthium from Tajikistan are markedly different from those from European, Middle Eastern, or other Asian locations and likely represent new chemotypes. © 2011 Reproduction is free for scientific studies.

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