Quantum transport efficiency and Fourier's law

We analyze the steady-state energy transfer in a chain of coupled two-level systems connecting two thermal reservoirs. Through an analytic treatment we find that the energy current is independent of the system size, hence violating Fourier's law of heat conduction. The classical diffusive behavior in Fourier's law of heat conduction can be recovered by introducing decoherence to the quantum systems constituting the chain. Implications of these results on energy transfer in biological light harvesting systems, and the role of quantum coherences and entanglement are discussed.Comment: 6 pages, 4 figure

Using PLS-SEM to Analyze the Effect of CSR on Corporate Performance: The Mediating Role of Human Resources Management and Customer Satisfaction: An Empirical Study in the Spanish Food and Beverage Manufacturing Sector

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). This is the published versión of a published work that apear in final form in Mathematics. To see the final versión see https://doi.org/10.3390/math9222973Although in recent decades corporate social responsibility (CSR) has been subjected to numerous studies in management and marketing literature about its impact on business results, the mechanism by which it affects performance has not been established. There is a lack of consensus when it comes to explaining how CSR actions are related to firm performance. Our research helps to understand this relationship through mediating effects such as CSR-oriented human resource management and customer satisfaction because employees and customers are critical stakeholders of companies and contribute directly to the determination of the corporate results. Through a study on a sample of small and medium-sized Spanish food and beverage manufacturing companies, and by using partial least squares structural equation modelling (PLS-SEM), we found that CSR does indeed impact business performance when CSR actions are mainly oriented towards more efficient management of human resources and customer satisfaction. In this way, the results lead us to conclude that depending on the stakeholder to which these actions are oriented, a specific orientation of the company’s CSR policy can be more efficient in corporate performanc

Quantum correlations and mutual synchronization

We consider the phenomenon of mutual synchronization in a fundamental quantum system of two detuned quantum harmonic oscillators dissipating into the environment. We identify the conditions leading to this spontaneous phenomenon showing that the ability of the system to synchronize is related to the existence of disparate decay rates and is accompanied by robust quantum discord and mutual information between the oscillators, preventing the leak of information from the system

Modelado del NO+ para pasajes del satélite S3-2 sobre el hemisferio sur

Se analiza teóricamente el comportamiento del ion NO , de importancia fundamental en los mecanismos de ionización de la región F, siendo los resultados confrontados con las mediciones del satélite S3-2 en su pasaje Nº 1550 sobre la región sudamericana durante un día solar y geomagnéticamente tranquilo, el 25 de marzo de 1976. El análisis, realizado desde el punto de vista químico solamente, muestra que: i) la producción de NO+ debida a la reacción entre N+ y 02, no puede ser ignorada. ii) la teoría expuesta lleva a resultados satisfactorios debajo de los 300 km solamente, ocurriendo un apartamiento significativo, en comparación con los resultados experimentales, arriba de esa altura. iii) el desacuerdo está requiriendo términos de transporte en la ecuación de continuidad arriba de los 300 km, y, quizás, un reajuste de los coeficientes de las reacciones y el uso de modelos actualizados de atmósfera neutra.The behavior of NO+, an ion of fundamental importance on the F- region ionization mechanisms, has been theoretically analyzed, and the results confronted with the S3-2 satellite measurements on its Nº 1550 passage over the south-american region during a solar and geomagnetic quiet day, the 25 of March 1976. The analysis, carried out only from the chemical point of view, shows that i) the NO+ production due to the N+ - O2 reaction can not be ignored. ii) The expounded theory leads to satisfactory results only below 300 km, with significant departure, compared with experimenat1 results, above that altitude. iii) the disagreement is requiring transport terms in the continuity equation above 300 km, and, perhaps, a readjustment of the reactions coefficients and the usage of up to date neutral atmosphere models.Asociación Argentina de Geofísicos y Geodesta

Pulsed current-voltage electrodeposition of stoichiometric Bi2Te3 nanowires and their crystallographic characterization by transmission electron backscatter diffraction

Bi2Te3 nanowires with diameters ranging from 25 to 270 nm, ultra-high aspect ratio, and uniform growth front were fabricated by electrodeposition, pulsing between zero current density during the off time and constant potential during the on time (pulsed-current-voltage method, p-IV). The use of zero current density during the off time is to ensure no electrodeposition is carried out and the system is totally relaxed. By this procedure, stoichiometric nanowires oriented perpendicular to the c-axis is obtained for the different diameters of porous alumina templates. In addition, the samples show a uniform growth front with ultra-high aspect ratio single crystal nanowires. The high degree of crystallinity was verified by transmission electron backscatter diffraction. This characterization revealed that the nanowires present both large single crystalline areas and areas with alternating twin configurations

Understanding treatment decisions from the perspective of people with relapsing remitting multiple Sclerosis: A critical interpretive synthesis

Background: Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system that mainly affects young adults. While there is no cure for MS, disease modifying treatments (DMTs) reduce the relapse rate and partial accrual of disability. More effective DMTs may have higher risks including life-threatening infections or secondary autoimmunity. The complexity and novelty of available treatments cause challenges for clinicians when prescribing treatments and for people with MS (PwMS) when deciding what trade-offs they are willing and ready to make. / Objective: To explore the experience of people with relapsing remitting MS (PwRRMS) and their perspectives in choosing treatments. / Methods: Critical interpretive synthesis was employed to review and synthesis the published literature. Eighty-three publications were selected in a multi-step systematic process. / Results: Findings are presented in four interrelated areas: the influence of the clinical evidence-base in decision making; the meaning of DMT efficacy for PwRRMS; the influence of models of decision-making and information acquisition practices in PwRRMS; and the importance of psychosocial dimensions in DMT decision making. Synthesis of the findings revealed that alongside medical and individual reasoning, contextual circumstances play an important role in making treatment decisions. / Conclusion: This review identifies and explains the importance of diverse contextual circumstances (clinical, social, psychological) that are important for PwRRMS when making treatment decisions. The findings demonstrate the importance of eliciting, understanding and addressing such contextual factors

Unidirectional reflection from an integrated 'taiji' microresonator

We study light transmission and reflection from an integrated microresonator device, formed by a circular microresonator coupled to a bus waveguide, with an embedded S-shaped additional crossover waveguide element that selectively couples counter-propagating modes in a propagation-direction-dependent way. The overall shape of the device resembles a 'taiji' symbol, hence its name. While Lorentz reciprocity is preserved in transmission, the peculiar geometry allows us to exploit the non-Hermitian nature of the system to obtain high-contrast unidirectional reflection with negligible reflection for light incident in one direction and a significant reflection in the opposite direction

Quantum correlations and synchronization measures

The phenomenon of spontaneous synchronization is universal and only recently advances have been made in the quantum domain. Being synchronization a kind of temporal correlation among systems, it is interesting to understand its connection with other measures of quantum correlations. We review here what is known in the field, putting emphasis on measures and indicators of synchronization which have been proposed in the literature, and comparing their validity for different dynamical systems, highlighting when they give similar insights and when they seem to fail.Comment: book chapter, 18 pages, 7 figures, Fanchini F., Soares Pinto D., Adesso G. (eds) Lectures on General Quantum Correlations and their Applications. Quantum Science and Technology. Springer (2017

Anisotropy of the superconducting state properties and phase diagram of MgB2 by torque magnetometry on single crystals

The angular and temperature dependence of the upper critical field Hc2 in MgB2 was determined from torque magnetometry measurements on single crystals. The Hc2 anisotropy gamma_H was found to decrease with increasing temperature, in disagreement with the anisotropic Ginzburg-Landau theory, which predicts that the gamma_H is temperature independent. This behaviour can be explained by the two band nature of superconductivity in MgB2. An analysis of measurements of the reversible torque in the mixed state yields a field dependent effective anisotropy gamma_eff, which can be at least partially explained by different anisotropies of the penetration depth and the upper critical field. It is shown that a peak effect in fields of about 0.85 Hc2 is a manifestation of an order-disorder phase transition of vortex matter. The H-T phase diagram of MgB2 for H//c correlates with the intermediate strength of thermal fluctuations in MgB2, as compared to those in high and low Tc superconductors.Comment: 12 pages, 8 figures, Physica C in print (invited paper for a special issue on MgB2