Bulgarian Academy of Sciences

About: Bulgarian Academy of Sciences is a government organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Catalysis & Coupling constant. The organization has 17989 authors who have published 36276 publications receiving 642820 citations. The organization is also known as: Bulgarian Academy of Sciences，簡稱：BAS & Balgarska Akademiya na Naukite.

Upgrading, Changing Competitive Pressures, and Diverse Practices in the East and Central European Apparel Industry

Abstract: After a period in the 1990s of rapid integration into the production and trade networks of the European Union (EU) (and to a lesser extent of the United States), clothing manufacturers in East and Central Europe have had to adjust quickly to the changing costs of production with EU accession, the rise of Chinese exports, and the 1 January 2005 final phaseout of quantitative quotas into major markets. In this paper we focus on the changing competitive pressures on clothing producers in the region and on the diversity of adjustments currently being made in response to these changes. In particular, we detail the wide range of adjustment strategies being adopted by firms in Slovakia and Bulgaria, and show how interregional price competition, downgrading, and geographical shifts in patterns of sourcing and production are articulated with imperatives to regionalized production for major markets, stabilization of supply networks, industrial upgrading, and the expansion of localized sourcing and domestic-marketin...

Search for narrow resonances using the dijet mass spectrum in pp collisions at √s=8 TeV

Abstract: Results are presented of a search for the production of new particles decaying to pairs of partons (quarks, antiquarks, or gluons), in the dijet mass spectrum in proton-proton collisions at sqrt(s) = 8 TeV. The data sample corresponds to an integrated luminosity of 4.0 inverse femtobarns, collected with the CMS detector at the LHC in 2012. No significant evidence for narrow resonance production is observed. Upper limits are set at the 95% confidence level on the production cross section of hypothetical new particles decaying to quark-quark, quark-gluon, or gluon-gluon final states. These limits are then translated into lower limits on the masses of new resonances in specific scenarios of physics beyond the standard model. The limits reach up to 4.8 TeV, depending on the model, and extend previous exclusions from similar searches performed at lower collision energies. For the first time mass limits are set for the Randall-Sundrum graviton model in the dijet channel.

Temporary immersion systems in plant biotechnology

Abstract: Plant tissue and organ cultures in vitro usually face technological challenges. When submerged cultivation of plant cells in a controlled environment is desired, the characteristic growth morphology and physiology of differentiated organ cultures present a problem in process scale-up. Temporary immersion systems (TIS) were developed several decades ago. These systems are providing the most natural environment for in vitro culture of plant shoots and seedlings. Over the past few years, TIS have been recognized as a perspective technology for plant micropropagation, production of plant-derived secondary metabolites, expression of foreign proteins, and potential solutions in phytoremediation. Nowadays, several TIS, operating on similar or divergent technological principles, have been developed and successfully applied in the cultivation of various plant in vitro systems, including somatic embryos and transformed root cultures. In this article, the operational principle and technological design of the most popular TIS are reviewed. In addition, recent examples of the application of temporary immersion technology for in vitro cultivation of plant tissue and organ cultures at laboratory and pilot scales are discussed. Finally, future prospects and challenges to the industrial realization of that fast-developing technique are outlined.

Model investigation of the Raman spectra of amorphous silicon

Abstract: A model for calculating the first-order Raman spectra of amorphous silicon (a-Si) without adjustable parameters is proposed. Calculations on the original 216-atom model of a-Si, generated by the algorithm of Wooten, Winer, and Weaire (WWW) are in very good agreement with experimental spectra and give further indication that the WWW cluster is a realistic model of moderately disordered a-Si. The TA-TO assignment of the low and high frequency bands is supported by direct numerical calculations of the phase quotient and the stretching character of the vibrational modes. The calculated participation ratios and correlation lengths of the vibrational modes indicate that the high-frequency TO-like modes are strongly localized on defects. The relative intensities of the TA-, LA-, and LO-like bands depend on the intermediate-range order, while that of the TO-like band mainly on the short-range order.

Search for top-quark partners with charge 5/3 in the same-sign dilepton final state

Abstract: A search for the production of heavy partners of the top quark with charge 5/3 is performed in events with a pair of same-sign leptons. The data sample corresponds to an integrated luminosity of 19.5 fb^(−1) and was collected at s√=8 TeV by the CMS experiment. No significant excess is observed in the data above the expected background, and the existence of top-quark partners with masses below 800 GeV is excluded at a 95% confidence level, assuming they decay exclusively to tW. This is the first limit on these particles from the LHC, and it is significantly more restrictive than previous limits.