Conductance Fluctuations Near the Two-Dimensional Metal-Insulator Transition

Measurements of conductance $G$ on short, wide, high-mobility Si-MOSFETs reveal both a two-dimensional metal-insulator transition (MIT) at moderate temperatures (1 $<~ T <$ 4~K) and mesoscopic fluctuations of the conductance at low temperatures ($T~ <$ 1~K). Both were studied as a function of chemical potential (carrier concentration $n_s$) controlled by gate voltage ($V_g$) and magnetic field $B$ near the MIT. Fourier analysis of the low temperature fluctuations reveals several fluctuation scales in $V_g$ that vary non-monotonically near the MIT. At higher temperatures, $G(V_g,B)$ is similar to large FETs and exhibits a MIT. All of the observations support the suggestion that the MIT is driven by Coulomb interactions among the carriers.Comment: 4 pages, LaTeX, physica.sty (slightly modified prabib.sty), Submitted to the 1997 Conference on Electronic Properties of Two-Dimensional System

Nonexponential Relaxations in a Two-Dimensional Electron System in Silicon

The relaxations of conductivity have been studied in a strongly disordered two-dimensional (2D) electron system in Si after excitation far from equilibrium by a rapid change of carrier density n_s at low temperatures T. The dramatic and precise dependence of the relaxations on n_s and T strongly suggests (a) the transition to a glassy phase as T->0, and (b) the Coulomb interactions between 2D electrons play a dominant role in the observed out-of-equilibrium dynamics.Comment: 5 pages, 5 figure

Collective Dynamics and Strong Pinning near the Onset of Charge Order in La1.48_{1.48}Nd0.4_{0.4}Sr0.12_{0.12}CuO4_{4}

The dynamics of charge-ordered states is one of the key issues in underdoped cuprate high-temperature superconductors, but static short-range charge-order (CO) domains have been detected in almost all cuprates. We probe the dynamics across the CO (and structural) transition in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$ by measuring nonequilibrium charge transport, or resistance $R$ as the system responds to a change in temperature and to an applied magnetic field. We find evidence for metastable states, collective behavior, and criticality. The collective dynamics in the critical regime indicates strong pinning by disorder. Surprisingly, nonequilibrium effects, such as avalanches in $R$, are revealed only when the critical region is approached from the charge-ordered phase. Our results on La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$ provide the long-sought evidence for the fluctuating order across the CO transition, and also set important constraints on theories of dynamic stripes.Comment: final version: 5 pages, 3 figures; includes Supplemental Material (3 pages, 7 figures

Current-voltage characteristics and vortex dynamics in highly underdoped La2−x_{2-x}Srx_{x}CuO4_{4}

The temperature dependence of the nonlinear current-voltage ($I$-$V$) characteristics in highly underdoped La$_{2-x}$Sr$_{x}$CuO$_{4}$ ($x=0.07$ and 0.08) thick films has been studied in both zero and perpendicular magnetic fields $H$. Power-law behavior of $V(I)$ is found for both $H=0$ and $H \neq 0$. The critical current $I_{c}$ was extracted, and its temperature and magnetic field dependences were studied in detail. The Berezinskii-Kosterlitz-Thouless physics dominates the nonlinear $I$-$V$ near the superconducting transition at $H=0$, and it continues to contribute up to a characteristic temperature $T_x(H)$. Nonlinear $I$-$V$ persists up to an even higher temperature $T_{h}(H)$ due to the depinning of vortices.Comment: 4 pages, 4 figures; Superstripes 2015 conferenc

ŠIRENJE DOMAŠAJA NEPRISTRASNOSTI JAVNOG BELEŽNIKA U DOMEN JAVNOG PRAVA

The paper analyzes the revision of the role of notaries in public law that in a new way is lighting impartiality as one of the basic features of notary profession. To the new reconstruction of notarial activities could be reached only with overcoming the classical triple state power sharing and the expansion of the idea of “new authorities”. Therefore, these impartiality of notaries could come through, first, by analyzing the spread of the principle of separation of powers. These considerations have led, then, to the independent regulatory bodies to which the public administration, as entities outside its organizational structure, transmits more public authorities. By analyzing the characteristics and functions of these bodies doctrine has identified a specific function that they were given, the function of impartial guarantees, which provides protection of private and collective interests and rights. To the similar findings came jurisprudence in relation to the notaries as a public service, which shows that it can allocate an entire complex of activities that precede the drafting of notarial act and that could be defend as an adjustment to the will of the parties to the rules of the legal system. In this new reconstructed notary role the impartiality appears in a completely new dimension: impartiality arises as a rule of action, not only when he participates in the processing of cases in which the parties wish to define and achieve some private interests, but also, and above all, that impartially guarantees to third parties, and to the state that such arrangement does not oppose of other protected interests. In this way reveals that the obligations of the notary’s impartiality does not stop at the borders of private law, thus its scope becomes much wider.U radu se analizira nepristrasnost javnog beležnika kao fenomen koji se u novije vreme otkriva i u domenu javnog prava. Temi nepristrasnosti javnog beležnika prilazi se putem, najpre, analize širenja načela podele vlasti, a nakon toga razmatranjem nezavisnih regulatornih tela, čije karakteristike i funkcije su pomogle doktrini da gradi novi pogled na funkcije notara. Danas se uočava da se može izdvojiti jedan kompleks poslova koji prethode sastavljanju javnobeležničke isprave i koji predstavljaju ne samo puko savetovanje, već mnogo kompleksnije delovanje - prilagođavanje volje stranaka pravilima pravnog sistema u cilju zaštite ne samo individualnog interesa stranaka već i kolektivnih interesa koje današnje društvo snažno afrmiše. Time se nepristrasnost pojavljuje u sasvim novoj dimenziji: ne samo kao garancija zaštite privatnih interesa stranaka već i podjednako značajnih drugih zaštićenih interesa. Zaključuje se da se obaveza javnobeležničke nepristrasnosti ne zaustavlja na granicama privatnog prava, što je do sada bilo opšteprihvaćeno gledište, već se prostire i na domen javnog prava, čime se njen domašaj pokazuje kao mnogo širi

Photovoltaic potential of the City of Požarevac

Photovoltaic power plants represent a good solution concerning electric energy supply under the condition that there are sufficiently available and suitable areas for their mounting. This study supports an opinion hypothesis that the City of Požarevac has at its disposal a considerable potential for energy production by photovoltaic power plants at the degraded areas. The geographic information systems were used to identify and create polygons for degraded areas, and the Energy capacity assessment tool was used in order to estimate the solar potential for this areas. The results showed that it would be possible to generate about 43% of the electric energy produced by thermal power plants “Kostolac A” and “Kostolac B” by construction and work of photovoltaic power plants in proposed locations. For a long-term standpoint, this project would prevent the emission of over 30 million tons of CO2 into the atmosphere. This study should contribute to the better understanding of local authorities regarding the potential for the use of solar energy, as well as, define of better principles, measures, instruments and policy to stimulate the application of solar energy to secure the requirements for electric energy.This is the peer-reviewed version of the article Doljak, D, Popović, D., Kuzmanović D., 2017. Photovoltaic potential of the City of Požarevac. Renewable and Sustainable Energy Reviews 73, 460-467. doi: 10.1016/j.rser.2017.01.15