The Coherence Field in the Field Perturbation Theory of Superconductivity

We re-examine the Nambu-Gorkov perturbation theory of superconductivity on the basis of the Bogoliubov-Valatin quasi-particles. We show that two different fields (and two additional analogous fields) may be constructed, and that the Nambu field is only one of them. For the other field- the coherence field- the interaction is given by means of two interaction vertices that are based on the Pauli matrices tau1 and tau3. Consequently, the Hartree integral for the off-diagonal pairing self-energy may be finite, and in some cases large. We interpret the results in terms of conventional superconductivity, and also discuss briefly possible implications to HTSC

Hydrogen leak detection device Patent

Development of device for detecting hydrogen in ambient environment

Sniffer used as portable hydrogen leak detector

Sniffer type portable monitor detects hydrogen in air, oxygen, nitrogen, or helium. It indicates the presence of hydrogen in contact with activated palladium black by a change in color of a thermochromic paint, and indicates the quantity of hydrogen by a sensor probe and continuous readout

Measurement of rolling friction by a damped oscillator

An experimental method for measuring rolling friction is proposed. The method is mechanically simple. It is based on an oscillator in a uniform magnetic field and does not involve any mechanical forces except for the measured friction. The measured pickup voltage is Fourier analyzed and yields the friction spectral response. The proposed experiment is not tailored for a particular case. Instead, various modes of operation, suitable to different experimental conditions, are discussed

The Field Perturbation Theory of the Double Correlated Phase in High Temperature Superconductors

The Double-Correlated phase in HTSC, and its treatment by field perturbation theory, is established. In particular, we define the ground state, the quasi-particle excitations, and construct an appropriate field. We also derive the unperturbed Hamiltonian, and the propagators for the unperturbed state. Then we discuss the perturbation Hamiltonian, and show that the Hartree diagram is significant for both the pseudogap and the superconductive order parameter, and suggest that it yields the major contribution to these parameters.Comment: 23 pages Of MSWord in PDF format, 1 figur

Influence of socioemotional wealth on non-family managers’ risk taking and product innovation in family businesses

Purpose: There is a growing interest in understanding family firms’ strategic behavior using the socioemotional wealth perspective. This study explores how family socioemotional wealth (SEW) dimensions influence non-family managers’ attitudes toward risk in the context of product innovation. We also examine whether managerial risk-taking mediates the relationship between SEW and product innovation. Design/methodology/approach: The study uses a sample of 150 family firms in the United Arab Emirates and collects data from family owners and non-family managers via self-administered questionnaires. We use SmartPLS structural equation modeling to test the conceptual model and the proposed hypotheses. Findings: The results indicate that SEW influences non-family managers’ risk-taking behavior in different magnitudes and directions, thus impacting firms’ product innovation. Moreover, risk-taking partially mediates the relationship between SEW dimensions and product innovation. Originality/value: While product innovation could be seen as a loss scenario for family firms due to the potential loss of SEW, growth, continuity, and reputation outweighed the desire to maintain control for the firms in this sample. Thus, these firms encourage non-family managers to take risks in product innovation

Do stochastic inhomogeneities affect dark-energy precision measurements?

The effect of a stochastic background of cosmological perturbations on the luminosity-redshift relation is computed to second order through a recently proposed covariant and gauge-invariant light-cone averaging procedure. The resulting expressions are free from both ultraviolet and infrared divergences, implying that such perturbations cannot mimic a sizable fraction of dark energy. Different averages are estimated and depend on the particular function of the luminosity distance being averaged. The energy flux, being minimally affected by perturbations at large z, is proposed as the best choice for precision estimates of dark-energy parameters. Nonetheless, its irreducible (stochastic) variance induces statistical errors on \Omega_{\Lambda}(z) typically lying in the few-percent range.Comment: 5 pages, 3 figures. Comments and references added. Typos corrected. Version accepted for publication in Phys. Rev. Let

Factors influencing patient loyalty to outpatient medical services: an empirical analysis of the UAE’s government healthcare system

Purpose The aim of this research is to uncover issues that inhibit patients' satisfaction and loyalty and identify factors that could enhance customer retention by government hospitals in the United Arab Emirates (UAE). The mediating impact of outpatient satisfaction on service quality, word of mouth (WoM), hospital image, outpatient–physician relationship and outpatient loyalty were tested. Design/methodology/approach The sample data used to test the hypotheses were drawn from a pool of patients served by a government healthcare agency in Abu Dhabi. Questionnaires were provided to 418 participants using methods such as short message service, e-mail and face-to-face delivery. The data were analyzed using SmartPLS 3.3.2 software. Findings The results indicate that service quality, WoM and outpatient–physician relationship positively impact outpatient satisfaction and indirectly effect outpatient loyalty; that hospital image positively impacts outpatient satisfaction and loyalty and has a partially mediating effect on loyalty; that waiting time satisfaction has no effect on outpatient satisfaction and no moderating effect on the outpatient satisfaction–loyalty relationship and that switching cost has a positive effect on loyalty but no moderating effect on the outpatient satisfaction–loyalty relationship. Research limitations/implications The first limitation of this study concerns the fact that only patients who had previously been served by these hospitals' outpatient units were included. Furthermore, the research was not able to obtain extensive findings related to the various factors that negatively impacted patient satisfaction and loyalty among all of the departments of government hospitals, such as inpatient care and emergency care. Practical implications Centered on the findings from this research, increasing switching costs would prevent patients from switching to other healthcare providers. Therefore, it has the potential to create a false loyalty or a hostage customer (Jones and Sasser, 1995). Additionally, making patients feel connected to their treatment plan and engaged in their care by developing a tool to maintain their enthusiasm about their health is important. It is therefore recommended that government hospital care providers and management consider providing online tools that patients can use to self-manage their care. Social implications The results regarding patients' satisfaction level suggest several areas for improvement. The first pertains to waiting area entertainment and comfort because patients indicated that there is not enough entertainment or ways to pass the time when waiting for services. In addition to enhancing the entertainment and comfort of waiting areas, government hospital staff should maintain contact with patients who are waiting to ensure that they are aware of the time they will spend. Another area for improvement is the parking lot. During summer, patients prefer to walk less in the sun, which causes them to seek parking closer to the door. Government hospital management should consider different methods for transporting patients closer to the door, such as golf carts or valet services. Originality/value This is the first study to investigate the mediating impact of outpatients' satisfaction between its antecedents and loyalty in the UAE. These results provide an improved understanding of the factors influencing patient choices and establish more accurate methods for increasing patient loyalty to retain more patients

Supergravity Higgs Inflation and Shift Symmetry in Electroweak Theory

We present a model of inflation in a supergravity framework in the Einstein frame where the Higgs field of the next to minimal supersymmetric standard model (NMSSM) plays the role of the inflaton. Previous attempts which assumed non-minimal coupling to gravity failed due to a tachyonic instability of the singlet field during inflation. A canonical K\"{a}hler potential with \textit{minimal coupling} to gravity can resolve the tachyonic instability but runs into the $\eta$-problem. We suggest a model which is free of the $\eta$-problem due to an additional coupling in the K\"{a}hler potential which is allowed by the Standard Model gauge group. This induces directions in the potential which we call K-flat. For a certain value of the new coupling in the (N)MSSM, the K\"{a}hler potential is special, because it can be associated with a certain shift symmetry for the Higgs doublets, a generalization of the shift symmetry for singlets in earlier models. We find that K-flat direction has $H_u^0=-H_d^{0*}.$ This shift symmetry is broken by interactions coming from the superpotential and gauge fields. This direction fails to produce successful inflation in the MSSM but produces a viable model in the NMSSM. The model is specifically interesting in the Peccei-Quinn (PQ) limit of the NMSSM. In this limit the model can be confirmed or ruled-out not just by cosmic microwave background observations but also by axion searches.Comment: matches the published version at JCA

Factor analysis using delta-rule wake-sleep learning

We describe a linear network that models correlations between real-valued visible variables using one or more real-valued hidden variables — a factor analysis model. This model can be seen as a linear version of the “Helmholtz machine”, and its parameters can be learned using the “wake-sleep ” method, in which learning of the primary “generative” model is assisted by a “recognition ” model, whose role is to fill in the values of hidden variables based on the values of visible variables. The generative and recognition models are jointly learned in “wake ” and “sleep ” phases, using just the delta rule. This learning procedure is comparable in simplicity to Oja’s version of Hebbian learning, which produces a somewhat different representation of correlations in terms of principal components. We argue that the simplicity of wake-sleep learning makes factor analysis a plausible alternative to Hebbian learning as a model of activity-dependent cortical plasticity.