A methodology for unified hardware-software design

Unified hardware-software design for digital computer

A virtual memory system design

Virtual memory management system with working set model suitable for microprogrammin

A loader algorithm for microprogramming

Loader algorithm for microprogramming in unified hardware-software desig

Universality of the 1/3 shot-noise suppression factor in nondegenerate diffusive conductors

Shot-noise suppression is investigated in nondegenerate diffusive conductors by means of an ensemble Monte Carlo simulator. The universal 1/3 suppression value is obtained when transport occurs under elastic collision regime provided the following conditions are satisfied: (i) The applied voltage is much larger than the thermal value; (ii) the length of the device is much longer than both the elastic mean free path and the Debye length. By fully suppressing carrier-number fluctuations, long range Coulomb interaction is essential to obtain the 1/3 value in the low-frequency limit.Comment: RevTex, 4 pages, 4 figure

Influence of nuclear structure on sub-barrier hindrance in Ni+Ni fusion

Fusion-evaporation cross sections for $^{64}$Ni+$^{64}$Ni have been measured down to the 10 nb level. For fusion between two open-shell nuclei, this is the first observation of a maximum in the $S$-factor, which signals a strong sub-barrier hindrance. A comparison with the $^{58}$Ni+$^{58}$Ni, $^{58}$Ni+$^{60}$Ni, and $^{58}$Ni+$^{64}$Ni systems indicates a strong dependence of the energy where the hindrance occurs on the stiffness of the interacting nuclei.Comment: Submitted to Phys. Rev. Lett. 4 pages, 3 figure

The magnesium paradigm in IRC+10216: Discovery of MgC4_4H+^+, MgC3_3N+^+, MgC6_6H+^+, and MgC5_5N+^+

We found four series of harmonically related lines in IRC\,+10216 with the Yebes\,40m and IRAM\,30m telescopes. The first series corresponds to a molecule with a rotational constant, $B$, of 1448.5994$\pm$0.0013 MHz and a distortion constant, $D$, of 63.45$\pm$1.15 Hz and covers upper quantum numbers from $J_u$=11 up to 33 (B1449). The second series is fitted with $B$=1446.9380$\pm$0.0098 MHz and $D$=91$\pm$23 Hz and covers upper quantum numbers from $J_u$=11 up to 17 (B1447). The third series is fitted with $B$=598.7495$\pm$0.0011 MHz and D=6.13$\pm$0.43 Hz and covers quantum numbers from $J_u$=26 up to 41 (B599). Finally, the frequencies of the last series of lines can be reproduced with $B$=594.3176$\pm$0.0026 MHz and $D$=4.92$\pm$1.16 Hz (B594). The large values of $D$ point toward four metal-bearing carriers. After exploring all plausible candidates containing Na, Al, Mg, and other metals, our ab initio calculations indicate that the cations MgC$_4$H$^+$, MgC$_3$N$^+$, MgC$_6$H$^+$, and MgC$_5$N$^+$ must be the carriers of B1449, B1447, B599, and B594, respectively. These cations could be formed by the radiative association of Mg$^+$ with C$_4$H, C$_3$N, C$_6$H, and C$_5$N, respectively. We calculated the radiative association rate coefficient of Mg$^+$ with C$_4$H, C$_3$N, C$_6$H, and C$_5$N and incorporated them in our chemical model. The results confirm that the Mg-bearing cations can be formed through these radiative association reactions in the outer layers of IRC\,+10216. This is the first time that cationic metal-bearing species have been found in space. These results provide a new paradigm on the reactivity of ionized metals with abundant radicals and open the door for further characterization of similar species in metal-rich astrophysical environments

Fachadas ventiladas activas para reducir la demanda de calefacción en los edificios de oficinas. El caso de España

This paper analyses the energy efficiency of a Ventilated Active Façade –VAF– applied to office buildings in Spain to reduce heating demand. This façade system consists of an outer layer element of 2 mm galvanized steel panels and a 3 cm air cavity where the ventilation air is preheated in winter and exhausted in summer. After defining 8 typical office typologies in Spain, 192 study cases are obtained where different parameters like the percentage of glass in façade, the orientation and the climatic zone of the buildings are considered. The energy demand of all these study cases is obtained using the official simulation tool of the Spanish Technical Building Regulation – CTE called LIDER. The results, in terms of reduction of heating demand, are presented in comparison with the minimum energetic requirements of CTE.En este artículo se analiza la eficiencia energética de una Fachada Ventilada Activa –FVA– aplicada a edificios de oficinas en España para reducir la demanda de calefacción. El sistema de fachada consiste en una hoja exterior de 2 mm de acero galvanizado y una cavidad de 3 cm donde el aire de ventilación es precalentado en invierno y extraído en verano. Tras definir 8 tipologías típicas, se han obtenido 192 casos de estudio en los que se consideran diferentes parámetros: la superficie acristalada, la orientación y la zona climática. El cálculo de la demanda energética de los casos de estudio ha sido llevado a cabo mediante el programa LIDER, el método general del Código Técnico de la Edificación – CTE. Los resultados obtenidos en términos de reducción de la demanda de calefacción, se muestran comparados con los mínimos requerimientos exigidos en el CTE

Plasticity and memory effects in the vortex solid phase of twinned YBa2Cu3O7 single crystals

We report on marked memory effects in the vortex system of twinned YBa2Cu3O7 single crystals observed in ac susceptibility measurements. We show that the vortex system can be trapped in different metastable states with variable degree of order arising in response to different system histories. The pressure exerted by the oscillating ac field assists the vortex system in ordering, locally reducing the critical current density in the penetrated outer zone of the sample. The robustness of the ordered and disordered states together with the spatial profile of the critical current density lead to the observed memory effects