Dynamical Behavior of a Squid Ring Coupled to a Quantized Electromagnetic Field

In this paper we investigate the dynamical behavior of a SQUID ring coupled to a quantized single-mode electromagnetic field. We have calculated the eigenstates of the combined fully quantum mechanical SQUID-field system. Interesting phenomena occur when the energy difference between the usual symmetric and anti-symmetric SQUID states equals the field energy . We find the low-energy lying entangled stationary states of the system and demonstrate that its dynamics is dominated by coherent Rabi oscillations.Comment: 6 pages, 2 figures. to be published on International Journal of Modern Physics

On the shape of a pure O-sequence

An order ideal is a finite poset X of (monic) monomials such that, whenever M is in X and N divides M, then N is in X. If all, say t, maximal monomials of X have the same degree, then X is pure (of type t). A pure O-sequence is the vector, h=(1,h_1,...,h_e), counting the monomials of X in each degree. Equivalently, in the language of commutative algebra, pure O-sequences are the h-vectors of monomial Artinian level algebras. Pure O-sequences had their origin in one of Richard Stanley's early works in this area, and have since played a significant role in at least three disciplines: the study of simplicial complexes and their f-vectors, level algebras, and matroids. This monograph is intended to be the first systematic study of the theory of pure O-sequences. Our work, making an extensive use of algebraic and combinatorial techniques, includes: (i) A characterization of the first half of a pure O-sequence, which gives the exact converse to an algebraic g-theorem of Hausel; (ii) A study of (the failing of) the unimodality property; (iii) The problem of enumerating pure O-sequences, including a proof that almost all O-sequences are pure, and the asymptotic enumeration of socle degree 3 pure O-sequences of type t; (iv) The Interval Conjecture for Pure O-sequences (ICP), which represents perhaps the strongest possible structural result short of an (impossible?) characterization; (v) A pithy connection of the ICP with Stanley's matroid h-vector conjecture; (vi) A specific study of pure O-sequences of type 2, including a proof of the Weak Lefschetz Property in codimension 3 in characteristic zero. As a corollary, pure O-sequences of codimension 3 and type 2 are unimodal (over any field); (vii) An analysis of the extent to which the Weak and Strong Lefschetz Properties can fail for monomial algebras; (viii) Some observations about pure f-vectors, an important special case of pure O-sequences.Comment: iii + 77 pages monograph, to appear as an AMS Memoir. Several, mostly minor revisions with respect to last year's versio

Resonant effects in a SQUID qubit subjected to non adiabatic changes

By quickly modifying the shape of the effective potential of a double SQUID flux qubit from a single-well to a double-well condition, we experimentally observe an anomalous behavior, namely an alternance of resonance peaks, in the probability to find the qubit in a given flux state. The occurrence of Landau-Zener transitions as well as resonant tunneling between degenerate levels in the two wells may be invoked to partially justify the experimental results. A quantum simulation of the time evolution of the system indeed suggests that the observed anomalous behavior can be imputable to quantum coherence effects. The interplay among all these mechanisms has a practical implication for quantum computing purposes, giving a direct measurement of the limits on the sweeping rates possible for a correct manipulation of the qubit state by means of fast flux pulses, avoiding transitions to non-computational states.Comment: 6 pages and 6 figures. The paper, as it is, has been accepted for publication on PRB on March 201

Optimizing Antenna Arrays for Spatial Multiplexing: Towards 6G Systems

In this paper we discuss the design of antenna arrays to be used for multiplexing applications. In particular, we introduce a suitable performance index to analyze the effect of the antenna geometry and the distribution of users for the overall performance of Multi-User Multiple Input Multiple Output systems. By means of such performance index, antenna arrays can be designed so as to increase the number of multiplexed parallel sub-channels. Numerical results show that a proper design could allow to double the contemporary served users and the overall system throughput

Hylan G-F 20: Review of its Safety and Efficacy in the Management of Joint Pain in Osteoarthritis

BACKGROUND: Osteoarthritis (OA) is a chronic degenerative joint disease that is a clinically and economically important disease. The increased prevalence of OA with aging, coupled to the demographics of aging populations, make OA a high priority health care problem. Viscosupplementation (VS) is a well-established treatment option in knee OA that is included in the professional guidelines for treatment of this joint disease, and could potentially provide a useful alternative in treating such patients with painful OA. Theoretically VS is an approach that should apply to all synovial joints. OBJECTIVES: The aim of this review is to assess the efficacy and safety of viscosupplementation with Hylan GF-20 (Synvisc(®)) in the management of joint pain in osteoarthritis. METHODS: THE FOLLOWING DATABASES WERE SEARCHED: Medline, Database of Abstract on Reviews and Effectiveness, Cochrane Database of Systematic Reviews. Furthermore, the lists of references of retrieved publications were manually checked for additional references. The search terms Review, Viscosupplementation, Osteoarthritis, Hyaluronic acid, Hyaluronan, Sodium Hyaluronate, Hylan GF-20, Synvisc, intra-articular injection were used to identify all studies relating to the use of Synvisc(®) viscosupplementation therapy in OA. RESULTS: Hylan GF-20 is a safe and effective treatment for decreasing pain and improving function in patients suffering from knee and hip OA but new evidences are emerging for its use in other joints

Alexithymia in anorexia and bulimia: Ubiquitous and primary trait?

Background: Alexithymia is associated to Eating Disorders (ED) and relevant for their prognosis but it is uncertain if it is ubiquitous, primary, and necessary for ED outburst. Methods: 124 ED outpatients and 80 healthy controls were compared with the Toronto Alexithymia Scale, personality, and psychopathology measures. Alexithymia and the other features are compared between anorexia nervosa (AN), bulimia nervosa (BN) and control groups. Alexithymia-based clusters were explored and compared with controls. Alexithymia traits are correlated with the other features. Results: Difficulty in identifying feelings was ubiquitous in ED subjects. A Non-Alexithymic Cluster (NAC) and an Alexithymic Cluster (ALC) were found with no difference in AN/BN distribution. ALC displays disordered personality and high psychopathology. Self-directiveness and interoceptive awareness were independently related to alexithymia and to depressive feelings. These two features along with depressive features completely accounted for alexithymia variance. Conclusion: Even though the difficulty in identifying feelings is ubiquitous in ED subjects, Alexithymia may not represent a primary trait but a complex dysfunction consequent to co-occurring character immaturity, altered interoceptive awareness, and depressive traits

Bioenergy chain building: a collective action perspective

Depletion of natural resources has become a key issue on the European policy agenda. Bottom-up measures have emerged in several countries with a view to promoting awareness campaigns and environmental sustainability, with the agenda set by individuals who start up collective initiatives at the local level. Such collective action provides an incentive to free-ride on the contribution of others. Social norms and the consequent behavior of individuals involved in collective action assume a key role in ensuring sustainable use of a public good, achieving significant, long-lasting success. The present study aims to ascertain which determinants most affect farmers’ willingness to contribute to common resources. The empirical study was conducted in an area in the province of Avellino (southern Italy) most affected by soil erosion problems. The study focused on the willingness of farmers to contribute to the public good through biomass production (Giant Cane). In all, 175 face-to-face questionnaires were administered to farmers in September-November 2013. Schwartz’s norm-activation model variables were collected. A Tobit model was implemented in which the dependent variable was the land farmers stated they were willing to cultivate with Giant Cane. Four on five psychological constructs, based on the NAM, proved statistically significant with the expected sign, showing that an altruistic behavioral approach is useful to predict the individual’s decision to adopt cooperation norms

Bioenergy chain building: a collective action perspective

Depletion of natural resources has become a key issue on the European policy agenda. Bottom-up measures have emerged in several countries with a view to promoting awareness campaigns and environmental sustainability, with the agenda set by individuals who start up collective initiatives at the local level. Such collective action provides an incentive to free-ride on the contribution of others. Social norms and the consequent behavior of individuals involved in collective action assume a key role in ensuring sustainable use of a public good, achieving significant, long-lasting success. The present study aims to ascertain which determinants most affect farmers’ willingness to contribute to common resources. The empirical study was conducted in an area in the province of Avellino (southern Italy) most affected by soil erosion problems. The study focused on the willingness of farmers to contribute to the public good through biomass production (Giant Cane). In all, 175 face-to-face questionnaires were administered to farmers in September-November 2013. Schwartz’s norm-activation model variables were collected. A Tobit model was implemented in which the dependent variable was the land farmers stated they were willing to cultivate with Giant Cane. Four on five psychological constructs, based on the NAM, proved statistically significant with the expected sign, showing that an altruistic behavioral approach is useful to predict the individual’s decision to adopt cooperation norms

A Novel Technique for Fingerprint Classification based on Fuzzy C-Means and Naive Bayes Classifier

Fingerprint classification is a key issue in automatic fingerprint identification systems. One of the main goals is to reduce the item search time within the fingerprint database without affecting the accuracy rate. In this paper, a novel technique, based on topological information, for efficient fingerprint classification is described. The proposed system is composed of two independent modules: the former module, based on Fuzzy C-Means, extracts the best set of training images; the latter module, based on Fuzzy C-Means and Naive Bayes classifier, assigns a class to each processed fingerprint using only directional image information. The proposed approach does not require any image enhancement phase. Experimental trials, conducted on a subset of the free downloadable PolyU database, show a classification rate of 91% over a 100 images test database using only 12 training examples

Sustainable EPM rubber compounds

Two important aspects that should be considered when designing new, sustainable rubber products are the bio-based character of the rubber compound ingredients and the recyclability of the vulcanized rubber product. In this work, both are addressed by compounding a thermoreversible cross-linked EPM rubber with pyrolysis carbon black and squalane as sustainable filler and plasticizer, respectively. The resulting rubber product is fully reprocessable in the melt and it displays material properties comparable to those of compounds with conventional additives with high retention of the material properties upon reprocessing