Transport anomaly at the ordering transition for adatoms on graphene

We analyze a manifestation of the partial ordering transition of adatoms on graphene in resistivity measurements. We find that Kekule mosaic ordering of adatoms increases sheet resistance of graphene, due to a gap opening in its spectrum, and that critical fluctuations of the order parameter lead to a non-monotonic temperature dependence of resistivity, with a cusp-like minimum at T=T_c.Comment: 4 pages, 1 figur

Specifics of the Fuel and Energy Complex Regulation: Seeking New Opportunities for Russian and International Aspects

The goal of this article is to define the main trends and possible ways of further development of the fuel and energy complex (FEC) in the Russian economy. The following tasks were solved to achieve this goal: to determine the place of the Russian FEC in the world economy, to assess the results achieved in implementing the energy strategy, and to identify promising directions for regulating the Russian FEC. The results of the study allow to conclude that certain positive indicators were achieved in the field of improving energy security, reducing energy intensity and increasing the budgetary efficiency of the FEC as part of the ES-2030 implementation. At the moment, the regulatory and legal framework has been formed and is being further developed, measures for import substitution in the FEC sectors are being taken, tax, customs and tariff policies are being improved, measures have been developed and implemented to increase the availability of energy infrastructure, etc. Further measures of state regulation of the FEC sectors should be aimed at the development of renewable energy economy, measures to encourage investments in the FEC, and the improvement of the system of tariff setting for electricity transmission services. Keywords: energy security, energy conservation, renewable energy sources (RES). JEL Classifications: L70, P20, P2

(Strange) Meson Interferometry at RHIC

We make predictions for the kaon interferometry measurements in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). A first order phase transition from a thermalized Quark-Gluon-Plasma (QGP) to a gas of hadrons is assumed for the transport calculations. The fraction of kaons that are directly emitted from the phase boundary is considerably enhanced at large transverse momenta K_T ~ 1 GeV/c. In this kinematic region, the sensitivity of the R_out/R_side ratio to the QGP-properties is enlarged. Here, the results of the 1-dimensional correlation analysis are presented. The extracted interferometry radii, depending on $K_T$, are not unusually large and are strongly affected by momentum resolution effects.Comment: 8 pages, 6 figure

Consideration of the Influence of Local Road Network Condition on the Social, Economic and Industrial Development of Ulus, the Republic of Sakha (Yakutia)

На основе существующих в настоящее время методов оптимизации дорожной сети выявлено, что в условиях Якутии не всегда надежно может быть определена техническая категория дороги и строительство дорог с твердым покрытием. В условиях Якутии при проектировании местной дорожной сети предлагаем учитывать качество жизни населения считать главным критерием. Обоснована необходимость строительства дорог с твердым покрытием с учетом природно-климатических факторов, предложена система критериев, которая определяла бы социально равноправное развитие территорий при помощи местной дорожной сети.On the basis of currently available methods for optimizing the road network it has been revealed that in the conditions of Yakutia the technical category of the road and construction of paved roads can not be always reliably determined. Under the conditions of Yakutia it is proposed to use the population quality of life as the main criterion while developing the design of the local road network. The necessity of the construction of paved roads, taking into account the climatic factors has been justified. And also we have proposed a system of criteria that would define the social and equitable regional development with the help of the local road networ

Consideration of the Influence of Local Road Network Condition on the Social, Economic and Industrial Development of Ulus, the Republic of Sakha (Yakutia)

На основе существующих в настоящее время методов оптимизации дорожной сети выявлено, что в условиях Якутии не всегда надежно может быть определена техническая категория дороги и строительство дорог с твердым покрытием. В условиях Якутии при проектировании местной дорожной сети предлагаем учитывать качество жизни населения считать главным критерием. Обоснована необходимость строительства дорог с твердым покрытием с учетом природно-климатических факторов, предложена система критериев, которая определяла бы социально равноправное развитие территорий при помощи местной дорожной сети.On the basis of currently available methods for optimizing the road network it has been revealed that in the conditions of Yakutia the technical category of the road and construction of paved roads can not be always reliably determined. Under the conditions of Yakutia it is proposed to use the population quality of life as the main criterion while developing the design of the local road network. The necessity of the construction of paved roads, taking into account the climatic factors has been justified. And also we have proposed a system of criteria that would define the social and equitable regional development with the help of the local road networ

Effect of Sc, Hf, and Yb Additions on Superplasticity of a Fine-Grained Al-0.4%Zr Alloy

This research was undertaken to study the way deformation behaves in ultrafine-grained (UFG)-conducting Al-Zr alloys doped with Sc, Hf, and Yb. All in all, eight alloys were studied with zirconium partially replaced by Sc, Hf, and/or Yb. Doping elements (X = Zr, Sc, Hf, Yb) in the alloys totaled 0.4 wt.%. The choice of doping elements was conditioned by the possible precipitation of Al3X particles with L12 structure in the course of annealing these alloys. Such particles provide higher thermal stability of a nonequilibrium UFG microstructure. Initial coarse-grained samples were obtained by induction casting. A UFG microstructure in the alloys was formed by equal-channel angular pressing (ECAP) at 225 °C. Superplasticity tests were carried out at temperatures ranging from 300 to 500 °C and strain rates varying between 3.3 × 10−4 and 3.3 × 10−1 s−1. The highest values of elongation to failure are observed in Sc-doped alloys. A UFG Al-0.2%Zr-0.1%Sc-0.1%Hf alloy has maximum ductility: at 450 °C and a strain rate of 3.3 × 10−3 s−1, relative elongation to failure reaches 765%. At the onset of superplasticity, stress (σ)–strain (ε) curves are characterized by a stage of homogeneous (uniform) strain and a long stage of localized plastic flow. The dependence of homogeneous (uniform) strain (εeq) on test temperature in UFG Sc-doped alloys is increasing uniformly, which is not the case for other UFG alloys, with εeq(T) dependence peaking at 350–400 °C. The strain rate sensitivity coefficient of flow stress m is small and does not exceed 0.26–0.3 at 400–500 °C. In UFG alloys containing no Sc, the m coefficient is observed to go down to 0.12–0.18 at 500 °C. It has been suggested that lower m values are driven by intensive grain growth and pore formation in large Al3X particles, which develop specifically at an ingot crystallization stage

Breakdown of the quantum Hall effect in graphene

We present experimental details on the carrier density dependent breakdown current in epitaxial graphene grown on SiC. We show that in this system even at very low carrier densities and moderate temperatures it is still possible to have a breakdown current large enough for metrologically accurate quantum Hall resistance measurements. This work paves the way for a simple bench top/turnkey quantum resistance standard

Yersinia pestis Caf1 Protein: Effect of Sequence Polymorphism on Intrinsic Disorder Propensity, Serological Cross-Reactivity and Cross-Protectivity of Isoforms.

Yersinia pestis Caf1 is a multifunctional protein responsible for antiphagocytic activity and is a key protective antigen. It is generally conserved between globally distributed Y. pestis strains, but Y. pestis subsp. microtus biovar caucasica strains circulating within populations of common voles in Georgia and Armenia were reported to carry a single substitution of alanine to serine. We investigated polymorphism of the Caf1 sequences among other Y. pestis subsp. microtus strains, which have a limited virulence in guinea pigs and in humans. Sequencing of caf1 genes from 119 Y. pestis strains belonging to different biovars within subsp. microtus showed that the Caf1 proteins exist in three isoforms, the global type Caf1NT1 (Ala48 Phe117), type Caf1NT2 (Ser48 Phe117) found in Transcaucasian-highland and Pre-Araks natural plague foci #4-7, and a novel Caf1NT3 type (Ala48 Val117) endemic in Dagestan-highland natural plague focus #39. Both minor types are the progenies of the global isoform. In this report, Caf1 polymorphism was analyzed by comparing predicted intrinsic disorder propensities and potential protein-protein interactivities of the three Caf1 isoforms. The analysis revealed that these properties of Caf1 protein are minimally affected by its polymorphism. All protein isoforms could be equally detected by an immunochromatography test for plague at the lowest protein concentration tested (1.0 ng/mL), which is the detection limit. When compared to the classic Caf1NT1 isoform, the endemic Caf1NT2 or Caf1NT3 had lower immunoreactivity in ELISA and lower indices of self- and cross-protection. Despite a visible reduction in cross-protection between all Caf1 isoforms, our data suggest that polymorphism in the caf1 gene may not allow the carriers of Caf1NT2 or Caf1NT3 variants escaping from the Caf1NT1-mediated immunity to plague in the case of a low-dose flea-borne infection

Effect of σ-Phase on the Strength, Stress Relaxation Behavior, and Corrosion Resistance of an Ultrafine-Grained Austenitic Steel AISI 321

This paper reported the results of research into the effect of Equal Channel Angular Pressing (ECAP) temperature and 1-h annealing temperature on mechanical properties, stress-relaxation resistance, and corrosion resistance of austenitic steel AISI 321L with strongly elongated thin δ-ferrite particles in its microstructure. The formation of α′-martensite and fragmentation of austenite grains takes place during ECAP. Ultrafine-grained (UFG) steels demonstrate increased strength. However, we observed a reduced Hall–Petch coefficient as compared with coarse-grained (CG) steels due to the fragmentation of δ-ferrite particles. UFG steel specimens were found to have 2–3 times higher stress-relaxation resistance as compared with CG steels. For the first time, the high stress-relaxation resistance of UFG steels was shown to stem from a internal stress-relaxation mechanism, i.e., the interaction of lattice dislocations with non-equilibrium grain boundaries. Short-time 1-h annealing of UFG steel specimens at 600–800 °C was found to result in the nucleation of σ-phase nanoparticles. These nanoparticles affect the grain boundary migration, raise strength, and stress-relaxation resistance of steel but reduce the corrosion resistance of UFG steel. Lower corrosion resistance of UFG steel was shown to be related to the formation of α′-martensite during ECAP and the nucleation of σ-phase particles during annealing

Two Isoforms of Yersinia Pestis Plasminogen Activator Pla: Intraspecies Distribution, Intrinsic Disorder Propensity, and Contribution to Virulence

It has been shown previously that several endemic Y. pestis isolates with limited virulence contained the I259 isoform of the outer membrane protease Pla, while the epidemic highly virulent strains possessed only the T259 Pla isoform. Our sequence analysis of the pla gene from 118 Y. pestis subsp. microtus strains revealed that the I259 isoform was present exclusively in the endemic strains providing a convictive evidence of more ancestral origin of this isoform. Analysis of the effects of the I259T polymorphism on the intrinsic disorder propensity of Pla revealed that the I259T mutation slightly increases the intrinsic disorder propensity of the C-terminal tail of Pla and makes this protein slightly more prone for disorder-based protein-protein interactions, suggesting that the T259 Pla could be functionally more active than the I259 Pla. This assumption was proven experimentally by assessing the coagulase and fibrinolytic activities of the two Pla isoforms in human plasma, as well as in a direct fluorometric assay with the Pla peptide substrate. The virulence testing of Pla-negative or expressing the I259 and T259 Pla isoforms Y. pestis subsp. microtus and subsp. pestis strains did not reveal any significant difference in LD50 values and dose-dependent survival assays between them by using a subcutaneous route of challenge of mice and guinea pigs or intradermal challenge of mice. However, a significant decrease in time-to-death was observed in animals infected with the epidemic T259 Pla-producing strains as compared to the parent Pla-negative variants. Survival curves of the endemic I259 Pla+ strains fit between them, but significant difference in mean time to death post infection between the Pla−strains and their I259 Pla+ variants could be seen only in the isogenic set of subsp. pestis strains. These findings suggest an essential role for the outer membrane protease Pla evolution in Y. pestis bubonic infection exacerbation that is necessary for intensification of epidemic process from endemic natural focality with sporadic cases in men to rapidly expanding epizootics followed by human epidemic outbreaks, local epidemics or even pandemics