Effect of pressure cycling on Iron: Signatures of an electronic instability and unconventional superconductivity

High pressure electrical resistivity and x-ray diffraction experiments have been performed on Fe single crystals. The crystallographic investigation provides direct evidence that in the martensitic $bcc \rightarrow hcp$ transition at 14 GPa the $\lbrace 110\rbrace_{bcc}$ become the $\lbrace 002\rbrace_{hcp}$ directions. During a pressure cycle, resistivity shows a broad hysteresis of 6.5 GPa, whereas superconductivity, observed between 13 and 31 GPa, remains unaffected. Upon increasing pressure an electronic instability, probably a quantum critical point, is observed at around 19 GPa and, close to this pressure, the superconducting $T_{c}$ and the isothermal resistivity ($0<T<300\,$K) attain maximum values. In the superconducting pressure domain, the exponent $n = 5/3$ of the temperature power law of resistivity and its prefactor, which mimics $T_{c}$, indicate that ferromagnetic fluctuations may provide the glue for the Cooper pairs, yielding unconventional superconductivity

Comparison of the Capacitance Method and the Microwave Impulse Method for Determination of Moisture Profiles in Building Materials

A comparison of the capacitance method and the microwave impulse method for the determination of moisture profiles in three typical porous building materials is presented in this paper. The basic principles of the measuring methods are given. The calibration process is described in detail. On the basis of the measured results, it can be concluded that the capacitance method provides better accuracy in the range of lower moisture content than to the microwave impulse method, which is more accurate for the highest values of moisture content.

Measurement of Moisture Storage Parameters of Building Materials

The moisture storage parameters of three different building materials: calcium silicate, ceramic brick and autoclaved aerated concrete, are determined in the hygroscopic range and overhygroscopic range. Measured sorption isotherms and moisture retention curves are then combined into moisture storage functions using the Kelvin equation. A comparison of measured results with global characteristics of the pore space obtained by mercury intrusion porosimetry shows a reasonable agreement; the median pore radii by volume are well within the interval given by the beginning and the end of the characteristic steep parts of the moisture retention curves

Near-Optimal Scheduling for LTL with Future Discounting

We study the search problem for optimal schedulers for the linear temporal logic (LTL) with future discounting. The logic, introduced by Almagor, Boker and Kupferman, is a quantitative variant of LTL in which an event in the far future has only discounted contribution to a truth value (that is a real number in the unit interval [0, 1]). The precise problem we study---it naturally arises e.g. in search for a scheduler that recovers from an internal error state as soon as possible---is the following: given a Kripke frame, a formula and a number in [0, 1] called a margin, find a path of the Kripke frame that is optimal with respect to the formula up to the prescribed margin (a truly optimal path may not exist). We present an algorithm for the problem; it works even in the extended setting with propositional quality operators, a setting where (threshold) model-checking is known to be undecidable

INFLUENCE OF YEAR AND ATONIK APPLICATION ON VARIABILITY OF SUGAR BEET ROOT YIELD AND DIGESTION

V poľných pokusoch s repou cukrovou bol v rokoch 1998 a 1999 sledovaný vplyv poveternostných podmienok ročníka a rôznych dávok aplikácie Atoniku na úrodu a digesciu repy cukrovej odrody Ranger. Výsledky pokusov potvrdili štatisticky vysoko preukazný vplyv pestovateľského ročníka na sledované ukazovatele produkcie repy cukrovej. V roku 1998, ktorý bol z hľadiska priebehu zrážok a teplôt menej priaznivý sme dosiahli v priemere nižšiu priemernú úrodu buliev (- 7,6 t.ha-1) a digesciu (- 0,2 °S) v porovnaní s rokom 1999. Zo sledovaných variantov aplikácie Atoniku sa na dosiahnutej úrode buliev (štatisticky preukazné) a digescii (štatisticky vysoko preukazné) významnejšie v porovnaní s neošetrenou kontrolou podielal variant ošetrenia Atonikom C (+ 6,7 t.ha-1, rel. 12,59 %, resp. + 0,6 °S, rel. 3,71 %).In 1998 and 1999 the effect of weather conditions and different doses of Atonik application on sugar beet root yield and digestion (cultivar Ranger) were studied in the field trial. The trial results confirmed statistically high significant effect of trial year weather conditions on above mentioned parameters. Comparing received results in the year 1998 to results in 1999 we found out lower root yield (- 7,6 t.ha-1) and digestion (- 0,2 t.ha-1) comparing with year 1999. We found out a significant effect of Atonik on root yield (+6,73 t.ha-1, rel.12,56 %) and digestion (+ 0,6 °S,rel. 3,71 %) on the variant C (Atonik treatment) comparing to values of control variant. In general we can evaluate the effect of Atonik application as high significant

INFLUENCE OF YEAR AND ATONIK APPLICATION ON VARIABILITY OF SUGAR BEET ROOT YIELD AND DIGESTION

V poľných pokusoch s repou cukrovou bol v rokoch 1998 a 1999 sledovaný vplyv poveternostných podmienok ročníka a rôznych dávok aplikácie Atoniku na úrodu a digesciu repy cukrovej odrody Ranger. Výsledky pokusov potvrdili štatisticky vysoko preukazný vplyv pestovateľského ročníka na sledované ukazovatele produkcie repy cukrovej. V roku 1998, ktorý bol z hľadiska priebehu zrážok a teplôt menej priaznivý sme dosiahli v priemere nižšiu priemernú úrodu buliev (- 7,6 t.ha-1) a digesciu (- 0,2 °S) v porovnaní s rokom 1999. Zo sledovaných variantov aplikácie Atoniku sa na dosiahnutej úrode buliev (štatisticky preukazné) a digescii (štatisticky vysoko preukazné) významnejšie v porovnaní s neošetrenou kontrolou podielal variant ošetrenia Atonikom C (+ 6,7 t.ha-1, rel. 12,59 %, resp. + 0,6 °S, rel. 3,71 %).In 1998 and 1999 the effect of weather conditions and different doses of Atonik application on sugar beet root yield and digestion (cultivar Ranger) were studied in the field trial. The trial results confirmed statistically high significant effect of trial year weather conditions on above mentioned parameters. Comparing received results in the year 1998 to results in 1999 we found out lower root yield (- 7,6 t.ha-1) and digestion (- 0,2 t.ha-1) comparing with year 1999. We found out a significant effect of Atonik on root yield (+6,73 t.ha-1, rel.12,56 %) and digestion (+ 0,6 °S,rel. 3,71 %) on the variant C (Atonik treatment) comparing to values of control variant. In general we can evaluate the effect of Atonik application as high significant

A Singular Differential Equation Stemming from an Optimal Control Problem in Financial Economics

We consider the ordinary differential equation x2u′′=axu′+bu−c(u′−1)2,x∈(0,x0), with a∈R,b∈R , c>0 and the singular initial condition u(0)=0, which in financial economics describes optimal disposal of an asset in a market with liquidity effects. It is shown in the paper that if a+b0 then there are infinitely many continuous solutions with indistinguishable asymptotics near 0. Moreover, it is proved that in the latter case there is precisely one solution u corresponding to the choice x 0=∞ which is such that 0≤u(x)≤x for all x>0, and that this solution is strictly increasing and concave

Verification and Control of Partially Observable Probabilistic Real-Time Systems

We propose automated techniques for the verification and control of probabilistic real-time systems that are only partially observable. To formally model such systems, we define an extension of probabilistic timed automata in which local states are partially visible to an observer or controller. We give a probabilistic temporal logic that can express a range of quantitative properties of these models, relating to the probability of an event's occurrence or the expected value of a reward measure. We then propose techniques to either verify that such a property holds or to synthesise a controller for the model which makes it true. Our approach is based on an integer discretisation of the model's dense-time behaviour and a grid-based abstraction of the uncountable belief space induced by partial observability. The latter is necessarily approximate since the underlying problem is undecidable, however we show how both lower and upper bounds on numerical results can be generated. We illustrate the effectiveness of the approach by implementing it in the PRISM model checker and applying it to several case studies, from the domains of computer security and task scheduling

Abstract Learning Frameworks for Synthesis

We develop abstract learning frameworks (ALFs) for synthesis that embody the principles of CEGIS (counter-example based inductive synthesis) strategies that have become widely applicable in recent years. Our framework defines a general abstract framework of iterative learning, based on a hypothesis space that captures the synthesized objects, a sample space that forms the space on which induction is performed, and a concept space that abstractly defines the semantics of the learning process. We show that a variety of synthesis algorithms in current literature can be embedded in this general framework. While studying these embeddings, we also generalize some of the synthesis problems these instances are of, resulting in new ways of looking at synthesis problems using learning. We also investigate convergence issues for the general framework, and exhibit three recipes for convergence in finite time. The first two recipes generalize current techniques for convergence used by existing synthesis engines. The third technique is a more involved technique of which we know of no existing instantiation, and we instantiate it to concrete synthesis problems

Synchronizing Automata on Quasi Eulerian Digraph

In 1964 \v{C}ern\'{y} conjectured that each $n$-state synchronizing automaton posesses a reset word of length at most $(n-1)^2$. From the other side the best known upper bound on the reset length (minimum length of reset words) is cubic in $n$. Thus the main problem here is to prove quadratic (in $n$) upper bounds. Since 1964, this problem has been solved for few special classes of \sa. One of this result is due to Kari \cite{Ka03} for automata with Eulerian digraphs. In this paper we introduce a new approach to prove quadratic upper bounds and explain it in terms of Markov chains and Perron-Frobenius theories. Using this approach we obtain a quadratic upper bound for a generalization of Eulerian automata.Comment: 8 pages, 1 figur