Search results for "PC"
showing 10 items of 2805 documents
Evolution of structural and electronic properties of TiSe2 under high pressure
2021
A pressure-induced structural phase transition and its intimate link with the superconducting transition was studied for the first time in TiSe2 up to 40 GPa at room temperature using X-ray diffraction, transport measurement, and first-principles calculations. We demonstrate the occurrence of a first-order structural phase transition at 4 GPa from the standard trigonal structure (S.G.P3¯m1) to another trigonal structure (S-G-P3¯c1). Additionally, at 16 GPa, the P3¯c1 phase spontaneously transforms into a monoclinic C2/m phase, and above 24 GPa, the C2/m phase returns to the initial P3¯m1 phase. Electrical transport results show that metallization occurs above 6 GPa. The charge density wave …
Investigation of AC Electrical Properties of MXene-PCL Nanocomposites for Application in Small and Medium Power Generation
2021
The paper examined Ti3C2Tx MXene (T—OH, Cl or F), which is prepared by etching a layered ternary carbide Ti3AlC2 (312 MAX-phase) precursor and deposited on a polycaprolactone (PCL) electrospun membrane (MXene-PCL nanocomposite). X-ray Diffraction analysis (XRD) and Scanning Electron Microscopy (SEM) indicates that the obtained material is pure Ti3C2 MXene. SEM of the PCL-MXene composite demonstrate random Ti3C2 distribution over the nanoporous membrane. Results of capacitance, inductance, and phase shift angle studies of the MXene-PCL nanocomposite are presented. It was found that the frequency dependence of the capacitance exhibited a clear sharp minima in the frequency range of 50 Hz to o…
Colossal barocaloric effects in the complex hydride Li$_{2}$B$_{12}$H$_{12}$
2021
Traditional refrigeration technologies based on compression cycles of greenhouse gases pose serious threats to the environment and cannot be downscaled to electronic device dimensions. Solid-state cooling exploits the thermal response of caloric materials to external fields and represents a promising alternative to current refrigeration methods. However, most of the caloric materials known to date present relatively small adiabatic temperature changes ($|\Delta T| \sim 1$ K) and/or limiting irreversibility issues resulting from significant phase-transition hysteresis. Here, we predict the existence of colossal barocaloric effects (isothermal entropy changes of $|\Delta S| \sim 100$ JK$^{-1}…
Stent oversizing or not-oversizing? An unresolved dilemma
2021
Primary PCI plus stent implantation is indicated for treatment of acute coronary syndrome. Technically, due to the difference in lumen diameter between vessel portions and stent size in some coronary arteries, post-expansion of the stent is usually necessary to match proximal reference diameter and optimize stent apposition. Incomplete stent apposition has been associated with increased risk of in stent restenosis (ISR) and stent thrombosis (1) despite new stent technologies have largely reduced this risk (2-3). Although new antiplatelet drugs showed a more rapid onset of action and a stronger effect (4-5), stent apposition remains an important risk factor for stent thrombosis. As stent pos…
De Regno Daniae et Norwegiae insulisq; adiacentibus, iuxta ac de Holsatia ducatu Sleswicensi et finitimis provincijs tractatus varij
1629
Index Port. grav. calc. Sign.: A-Z8, 2A-2G8
Time-resolved fluorescence and fourier transform infrared spectroscopic investigations of lateral packing defects and superlattice domains in composi…
2003
Time-resolved fluorescence and Fourier transform infrared spectroscopies were used to investigate the lateral organization of lipids in compositionally uniform and fully equilibrated 1-palmitoyl-2-oleoyl-phosphatidylcholine/cholesterol (POPC/CHOL) liposomes prepared by a recently devised low-temperature trapping method. Independent fluorescence decay lifetime and rotational dynamics parameters of diphenylhexatriene (DPH) chain-labeled phosphatidylcholine (DPH-PC) in these liposomes were recovered from the time-resolved fluorescence measurements as a function of cholesterol molar fraction (X(CHOL)) at 23 degrees C. The results indicate significantly greater lifetime heterogeneity, shorter av…
Factores determinantes de la intención de cambio estratégico: el papel de los equipos directivos
2010
ResumenLa capacidad de una empresa para adaptarse y responder a las oportunidades y presiones del entorno es uno de los aspectos más importantes en la búsqueda de la competitividad y de la supervivencia. Este trabajo pretende mejorar la comprensión de los factores que influyen en la intención de impulsar cambios en el contenido de la estrategia, analizando los factores motivadores y de resistencia tradicionalmente considerados, así como el papel facilitador de las características de los equipos directivos. Nuestros resultados resaltan que la heterogeneidad de los equipos directivos facilita la predisposición a impulsar cambios en las estrategias competitivas y corporativas, y que los cambio…
Un sistema de ayuda a la escritura de textos estructurados en LaTeX para estudiantes con déficit visual
2011
La redacción y presentación de documentos estructurados grandes, especialmente si requieren notación matemática, puede resultar difícil para los alumnos ciegos o con déficit visual usando editores clásicos. El proyecto que se propone, aún en fase inicial, consiste en un sistema de ayuda a la escritura de textos en LATEX[2] que reconozca como órdenes simples de voz las principales marcas de este lenguaje y emita también por voz indicaciones útiles como errores, mensajes de estado, etc. Se discuten las ventajas del uso de lenguajes de marcado para personas ciegas, entre otras la posibilidad de conversión automática a cualquier otro formato (HTML,XML,...), la posibilidad de inclusión de tablas…
On extremal cases of Hopcroft’s algorithm
2010
AbstractIn this paper we consider the problem of minimization of deterministic finite automata (DFA) with reference to Hopcroft’s algorithm. Hopcroft’s algorithm has several degrees of freedom, so there can exist different executions that can lead to different sequences of refinements of the set of the states up to the final partition. We find an infinite family of binary automata for which such a process is unique, whatever strategy is chosen. Some recent papers (cf. Berstel and Carton (2004) [3], Castiglione et al. (2008) [6] and Berstel et al. (2009) [1]) have been devoted to find families of automata for which Hopcroft’s algorithm has its worst execution time. They are unary automata as…
Hopcroft’s Algorithm and Cyclic Automata
2008
Minimization of deterministic finite automata is a largely studied problem of the Theory of Automata and Formal Languages. It consists in finding the unique (up to isomorphism) minimal deterministic automaton recognizing a set of words. The first approaches to this topic can be traced back to the 1950’s with the works of Huffman and Moore (cf. [12,15]). Over the years several methods to solve this problem have been proposed but the most efficient algorithm in the worst case was given by Hopcroft in [11]. Such an algorithm computes in O(n log n) the minimal automaton equivalent to a given automaton with n states. The Hopcroft’s algorithm has been widely studied, described and implemented by …