299 research outputs found
Electronic structure of the compound from ab initio local interactions
We used fully correlated ab initio calculations to determine the effective
parameters of Hubbard and t - J models for the thermoelectric misfit compound
. As for the family the Fermi level orbitals
are the orbitals of the cobalt atoms ; the being always lower
in energy by more than 240\,meV. The electron correlation is found very large
as well as the parameters fluctuations as a function of the
structural modulation. The main consequences are a partial electrons
localization and a fluctuation of the in-plane magnetic exchange from AFM to
FM. The behavior of the Seebeck coefficient as a function of temperature is
discussed in view of the ab initio results, as well as the 496\,K phase
transition
Numerical simulation evidence of dynamical transverse Meissner effect and moving Bose glass phase
We present 3D numerical simulation results of moving vortex lattices in
presence of 1D correlated disorder at zero temperature. Our results with field
tilting confirm the theoritical predictions of a moving Bose glass phase,
characterized by transverse pinning and dynamical transverse Meissner effect,
the moving flux lines being localized along the correlated disorder direction.
Beyond a critical transverse field, vortex lines exhibit along all their length
a "kink" structure resulting from an effective static "tin roof" pinning
potential in the transverse direction.Comment: 5 pages, 4 figure
Majorana Spin Liquids, Topology and Superconductivity in Ladders
We theoretically address spin chain analogs of the Kitaev quantum spin model
on the honeycomb lattice. The emergent quantum spin liquid phases or Anderson
resonating valence bond (RVB) states can be understood, as an effective model,
in terms of p-wave superconductivity and Majorana fermions. We derive a
generalized phase diagram for the two-leg ladder system with tunable
interaction strengths between chains allowing us to vary the shape of the
lattice (from square to honeycomb ribbon or brickwall ladder). We evaluate the
winding number associated with possible emergent (topological) gapless modes at
the edges. In the Az phase, as a result of the emergent Z2 gauge fields and
pi-flux ground state, one may build spin-1/2 (loop) qubit operators by analogy
to the toric code. In addition, we show how the intermediate gapless B phase
evolves in the generalized ladder model. For the brickwall ladder, the
phase is reduced to one line, which is analyzed through perturbation theory in
a rung tensor product states representation and bosonization. Finally, we show
that doping with a few holes can result in the formation of hole pairs and
leads to a mapping with the Su-Schrieffer-Heeger model in polyacetylene; a
superconducting-insulating quantum phase transition for these hole pairs is
accessible, as well as related topological properties.Comment: 25 pages, 10 figures, final version - to be published in PR
Goal-Oriented Scheduling in Sensor Networks With Application Timing Awareness
— Taking inspiration from linguistics, the communications theoretical community has recently shown a significant recent interest in pragmatic, or goal-oriented, communication. In this paper, we tackle the problem of pragmatic communication with multiple clients with different, and potentially conflicting, objectives. We capture the goal-oriented aspect through the metric of Value of Information (VoI), which considers the estimation of the remote process as well as the timing constraints. However, the most common definition of VoI is simply the Mean Square Error (MSE) of the whole system state, regardless of the relevance for a specific client. Our work aims to overcome this limitation by including different summary statistics, i.e., value functions of the state, for separate clients, and a diversified query process on the client side, expressed through the fact that different applications may request different functions of the process state at different times. A query-aware Deep Reinforcement Learning (DRL) solution based on statically defined VoI can outperform naive approaches by 15-20%
Textile characteristics of fiber from Huacaya alpacas (Vicugna pacos)
Fiber from alpacas represents a substantial component of economic output for South American countries. In this study it determined the textile characteristics of fibers obtained from Huacaya alpacas raised at the South American Camelids Research and Development Center-Lachocc (CRDC-Lachocc) located at The National University of Huancavelica (UNH). Fleece samples were obtained from the mid-side rib area of 74 white alpacas (42 females and 32 males) of varying ages. The Average Fiber Diameter (AFD), Standard Deviation of the Average Fiber Diameter (SDAFD), Fiber Diameter Coefficient of Variation (FDCV), Comfort Factor (CF) and Staple Length (SL) were measured as textile characteristics and related to sex and age group. Most of the fleece samples could be classified as baby alpaca fleece according to the Peruvian Technical Standard classification (231.301.2014). Sex had no influence on any textile characteristic (p > 0.05). Meanwhile, age affected only AFD and CF (p < 0.05). Together the results indicated that alpacas farmed at CRDC-Lachocc had good potential to produce high quality fibers
Size and number variation of adipocytes during the growth of Rasa Aragonesa lambs
The size and number of adipocytes of different fat depots was studied in 45 male lambs of the
Rasa Aragonesa breed, distributed in three groups of 15 lambs (G12, G24, G36), slaughtered respectively at
l 1.7 0.67,24.5 0.57 and 35.8 ? 1.74 kg live weight (LW) and at an age of 32 5, 89 8 and 123 & 8 days.
G12 lambs were slaughtered on the day of weaning, G24 and G36 lambs were weaned respectively at
16.2 & 1.32 and 18.3 r 2.46 kg LW and were fed from then onwards on concentrated fodder and barley straw
ad libitum until they were slaughtered. The results obtained show that there is a significant increase in the
amount of fat deposited in three internal (omental, mesenteric and kidney knob and channel) fat depots as the
LW at slaughter increases (P<O.Ol). A similar phenomenon occurs in the size of the adipocytes, hypertrophy
being more evident between 24 and 36 kg (Px0.01) than between 12 and 24 kg, except in the intermuscular fat
depot, where the differences were between the two most extreme weights (P<O.Ol). The number of adipocytes
in the omental and mesenteric fat depots increased significantly during the period of the study while
no variation occurred in the kidney knob and channel fat depot during the same period."Variation de la taille et
Aragonesa'! On a étudié la taille et le nombre des adipocytes de différents tissus adipeux chez 45 agneaux
3 groupes de 15 agneaux (G12, G24, G36), abattus
respectivement à 11,7 0,67; 24,5 0,57 et 35,8 1,74 kg de poids vif (PV) et 32 5; 89 8 y 123 2 8 jours
d'âge. Les agneaux du G12 ont été abattus le jour du sevrage; ceux du G24 et du G36 ont été sevrés
respectivementà 16,2 -+ 1,32 y 18,3 2 2,46 kg de PV, et ont eu à leur disposition de l'aliment concentré et de la
paille d'orge "ad libitum" jusqu'au le moment de l'abattage. Les résultats obtenus montrent une augmentation
significative de la quantité de graisse deposée dans les trois dépôts gras internes (omental, mésentérique,
pelvico-rénal) au fur età mesure de l'augmentation du PV d'abattage (P<O,OI). Des résultats semblables ont été
trouvés avec la taille des adipocytes car elle augmente avec le PL( l'hypertrophie étant plus marquée entre 24 et
36 kg (P<O,OI) qu' entre 12 et 24 kg, sauf dans le tissu intermusculaire dans lequel les différences ont été entre
les deux poids extrêmes (P<O,Ol). Le nombre des adipocytes dans les tissus omental et mésentérique a
augmenté significativement pendant la période étudiée (P<O,OI), tandis que dans le tissu pelvico-rénal il n'y a
pas eu de variation pendant cette période
Lipogenic enzyme activity in growing Rasa Aragonesa lambs
- The lipogenic enzyme activity of the following enzymes was studied: Glycerol 3-phosphate
dehydrogenase (G3PDH), fatty acids synthetase (FAS), NADP-Malate dehydrogenase (ME) and Glucose
6-phosphate dehydrogenase (G6PDH) in five fat depots (omental, OM; mesenteric, MES; kidney knob and
channel, KKC; subcutaneous, SC; intermuscular, IM) in 45 male Rasa Aragonesa lambs divided into three
groups of 15 lambs (G12, G24, G36). They were slaughtered respectively at 11.70 r 0.67; 24.50 -c 0.57 and
35.80 f 1.74 kg of live weight (LW) and at 32 f 5; 89 f 8, and 123 f 8 days old. The G12 lambs were
slaughtered on the day of weaning, having consumed solely their mother's milk; those in the G24 and G36
groups were weaned at 16.20 -c 1.32 and 18.30 i 2.46 kg LW respectively, were fed from then onward
increase in the activity of the G3PDH and FAS lipogenic enzymes was observed. The increase inthe 'de novo'
synthesis (FAS) at 36 kg LW was matched by G6PDH activity, which indicates greater use of acetate as a
precursor of fatty acids. Furthermore, the maintenance of ME activity during the period studied would indicate
that the glucose rate utilization for the fatty acids synthesis was not modified throughout this period."Activité enzymatique lipogénique chez l'agneau de race Rasa Aragonesa au cours de la
croissance". On a étudié l'activité enzymatique lipogénique des enzymes Glycérol3-phosphate déhydrogénase
(G3PDH), Synthétase des acides gras (SAG), NADP-Malate déhydrogénase (EM) et Glucose 6-phosphate
déhydrogénase (GGPDH), dans 5 tissus adipeux (omental, OM ; mésentérique, MES ; pelvien-rénal, PVR ;
sous-cutané, SC ; et intermusculaire, /M) chez 45 agneaux mâles de race Rasa Aragonesa répartis en trois lots
de 15 agneaux (G12, G24, G36), abattus respectivement à 11,70 0,67; 24,50 -t 0,57 et 35,80 1,74 kg de
poids vif (PV) et 32 f 5 ; 89 & 8 et 123 8 jours d'âge. Les agneaux du lot G12 ont été abattus le jour du
sevrage et ont ingéré uniquement du lait de la mère ; ceux du lot G24 et du lot G36 ont été sevrés à 16,20
1,32 et 18,30 -r- 2,46 kg de PV, et ont ingéré après le sevrage de l'aliment concentré et de la paille d'orge ad
libitum jusqu'à l'abattage. Entre 24 et 36 kg de PV, on a observé une augmentation des activités des enzymes
G3PDH et SAG. L'augmentation de la synthèse "de novo" (SAG) B 36 kg de PV a éte accompagnée par une
augmentation de l'activité de la GGPDH, qui pourrait indiquer une utilisation plus élevée de l'acétate comme
précurseur des acides gras. D'autre part, l'absence de variation dans l'activité de I'EM pourrait indiquer que
l'utilisation du glucose pour la synthèse des acides gras n'a pas été modifiée pendant la période ét
An Exploration of the Ozone Dimer Potential Energy Surface
The (O3)2 dimer potential energy surface is thoroughly explored at the ab initio CCSD(T) computational level. Five minima are characterized with binding energies between 0.35 and 2.24 kcal/mol. The most stable may be characterized as slipped parallel, with the two O3 monomers situated in parallel planes. Partitioning of the interaction energy points to dispersion and exchange as the prime contributors to the stability, with varying contributions from electrostatic energy, which is repulsive in one case. Atoms in Molecules analysis of the wavefunction presents specific O⋯O bonding interactions, whose number is related to the overall stability of each dimer. All internal vibrational frequencies are shifted to the red by dimerization, particularly the antisymmetric stretching mode whose shift is as high as 111 cm−1. In addition to the five minima, 11 higher-order stationary points are identified
- …